Boston Private Financial (BPFH) 10-K 28 Feb 18 2017 Q4 Annual report Financial data

Document Entity Information Doc

Document Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 23, 2018	Jun. 30, 2017
Document Information [Line Items]
Entity Registrant Name	BOSTON PRIVATE FINANCIAL HOLDINGS INC
Entity Central Index Key	821,127
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q4
Amendment Flag	false
Entity Common Stock, Shares Outstanding		84,264,182
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,263,534,759

Consolidated Balance Sheet Stat

Consolidated Balance Sheet Statement - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and cash equivalents	$ 120,541	$ 106,557
Investment securities available-for-sale (amortized cost of $1,182,427 and $1,283,161 at December 31, 2017 and 2016, respectively)	1,170,328	1,264,132
Investment securities held-to-maturity (fair value of $73,781 and $92,604 at December 31, 2017 and 2016, respectively)	74,576	93,079
Stock in Federal Home Loan Bank and Federal Reserve Bank	59,973	44,077
Loans held for sale	4,697	3,464
Total loans	6,505,028	6,114,354
Less: Allowance for loan losses	74,742	78,077
Net loans	6,430,286	6,036,277
Other real estate owned (“OREO”)	0	1,690
Premises and equipment, net	37,640	31,827
Goodwill	75,598	142,554
Intangible assets, net	16,083	26,725
Fees receivable	11,154	13,400
Accrued interest receivable	22,322	20,479
Deferred income taxes, net	29,031	55,460
Other assets	259,515	130,753
Total assets	8,311,744	7,970,474
Liabilities:
Deposits	6,510,246	6,085,146
Securities sold under agreements to repurchase	32,169	59,624
Federal funds purchased	30,000	80,000
Federal Home Loan Bank borrowings	693,681	734,205
Junior subordinated debentures	106,363	106,363
Other liabilities	135,880	119,683
Total liabilities	7,508,339	7,185,021
Redeemable Noncontrolling Interests	17,461	16,972
Shareholders’ Equity:
Preferred stock, $1.00 par value; authorized: 2,000,000 shares; Series D, 6.95% Non-Cumulative Perpetual, issued and outstanding: 50,000 shares at December 31, 2017 and December 31, 2016; liquidation preference: $1,000 per share	47,753	47,753
Common stock, $1.00 par value; authorized: 170,000,000 shares; issued and outstanding: 84,208,538 shares at December 31, 2017 and 83,731,769 shares at December 31, 2016	84,208	83,732
Additional paid-in capital	607,929	597,454
Retained earnings/ (accumulated deficit)	49,526	47,929
Accumulated other comprehensive income/ (loss)	(8,658)	(12,548)
Total Company's shareholders’ equity	780,758	764,320
Noncontrolling interests	5,186	4,161
Total shareholders' equity	785,944	768,481
Total liabilities, redeemable noncontrolling interests and shareholders’ equity	$ 8,311,744	$ 7,970,474

Consolidated Balance Sheet Sta3

Consolidated Balance Sheet Statement Parenthetical - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment securities available-for-sale at amortized cost	$ 1,182,427	$ 1,283,161
Investment securities held-to-maturity at fair value	$ 73,781	$ 92,604
Preferred Stock, Par Value Per Share	$ 1	$ 1
Preferred Stock, Shares Authorized	2,000,000	2,000,000
Common Stock, Par Value Per Share	$ 1	$ 1
Common Stock, Shares Authorized	170,000,000	170,000,000
Common Stock, Shares, Issued	84,208,538	83,731,769
Common Stock, Shares, Outstanding	84,208,538	83,731,769
Series D Preferred Stock [Member]
Preferred Stock, Par Value Per Share	$ 1
Preferred Stock, Shares Issued	50,000	50,000
Preferred Stock, Shares Outstanding	50,000	50,000
Preferred Stock, Liquidation Preference Per Share	$ 1,000	$ 1,000

Consolidated Statement of Opera

Consolidated Statement of Operations - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and dividend income:
Loans		$ 228,964	$ 201,349	$ 192,184
Taxable investment securities		6,393	6,230	4,403
Non-taxable investment securities		6,622	5,754	4,758
Mortgage-backed securities		13,391	12,416	10,933
Federal funds sold and other		3,325	1,890	1,390
Total interest and dividend income		258,695	227,639	213,668
Interest expense:
Deposits		20,884	16,571	16,002
Federal Home Loan Bank borrowings		9,883	8,008	7,959
Junior subordinated debentures		2,919	2,427	3,875
Repurchase agreements and other short-term borrowings		323	195	62
Total interest expense		34,009	27,201	27,898
Net interest income		224,686	200,438	185,770
Provision/ (credit) for loan losses		(7,669)	(6,935)	(1,555)
Net interest income after provision/ (credit) for loan losses		232,355	207,373	187,325
Fees and other income:
Investment management fees		45,515	44,410	45,694
Wealth advisory fees		52,559	50,581	50,437
Wealth management and trust fees		45,362	43,980	51,309
Other banking fee income		8,915	12,050	8,440
Gain on sale of loans, net		451	667	1,207
Gain/ (loss) on sale of investments, net		376	521	236
Gain/ (loss) on OREO, net		(46)	306	124
Gain/ (loss) on sale of affiliates or offices		(1,264)	2,862	0
Other		2,098	3,410	3,722
Total fees and other income		153,966	158,787	161,169
Operating expense:
Salaries and employee benefits		178,406	163,767	159,401
Occupancy and equipment		30,165	28,007	27,861
Professional services		13,763	11,576	12,861
Marketing and business development		7,766	7,626	9,063
Information systems		21,796	19,229	17,020
Amortization of intangibles		5,601	6,282	6,711
Impairment of goodwill		24,901	9,528	0
FDIC insurance		2,969	3,484	3,979
Restructuring		0	2,017	3,724
Other		14,569	13,437	14,561
Total operating expense		299,936	264,953	255,181
Income before income taxes		86,385	101,207	93,313
Income tax expense	[1]	46,196	30,963	30,392
Net income from continuing operations		40,189	70,244	62,921
Net income from discontinued operations	[2]	4,870	5,541	6,411
Net income before attribution to noncontrolling interests		45,059	75,785	69,332
Less: Net income attributable to noncontrolling interests		4,468	4,157	4,407
Net income attributable to the Company		40,591	71,628	64,925
Adjustments to net income attributable to the Company to arrive at net income attributable to common shareholders		(4,887)	(4,063)	(3,011)
Net income attributable to common shareholders for basic earnings per share calculation		$ 35,704	$ 67,565	$ 61,914	[3]
Basic earnings per share attributable to common shareholders:
From continuing operations:		$ 0.37	$ 0.76	$ 0.69
From discontinued operations:		0.06	0.07	0.08
Total attributable to common shareholders:		0.43	0.83	0.77
Diluted earnings per share attributable to common shareholders:
From continuing operations:		0.36	0.74	0.66
From discontinued operations:		0.06	0.07	0.08
Total attributable to common shareholders:		$ 0.42	$ 0.81	$ 0.74
Common Stock [Member]
Basic earnings per share attributable to common shareholders:
Weighted average basic common shares outstanding		82,430,633	81,264,273	80,885,253
Diluted earnings per share attributable to common shareholders:
Weighted average diluted common shares outstanding		84,802,565	83,209,126	83,393,090	[3],[4]
[1]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.
[2]	The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively
[3]	The Company presents its EPS based on the treasury stock method. The Company reverted to the treasury stock presentation from the two-class presentation due to the immaterial number of participating shares outstanding as of March 31, 2016. There is no difference between the calculation of EPS based on the treasury stock method and the calculation of EPS based on the two-class method for the year ended December 31, 2017.If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2016. Net income attributable to common shareholders would have been reduced by an additional $4 thousand, for the year ended December 31, 2016. The allocation of net income to participating securities would have been $8 thousand for the year ended December 31, 2016, reducing net income attributable to common shareholders by a total of $12 thousand for the same period. Basic EPS would not change. Weighted average diluted shared outstanding would have been reduced by 7,185 shares for the year ended December 31, 2016. Diluted EPS would not change. If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2015. Net income attributable to common shareholders would have been reduced by an additional $90 thousand for the year ended December 31, 2015, and the allocation of net income to participating securities would have been $92 thousand for the same period, reducing net income attributable to common shareholders by a total of $182 thousand, for the same period. Total basic EPS and basic EPS from continuing operations would each decrease by $0.01 per share for the year ended December 31, 2015. Weighted average diluted shares outstanding would have been reduced by 167,937 shares for the same period. Diluted EPS would not change.
[4]	The diluted EPS computations for the years ended December 31, 2017, 2016, and 2015 do not assume the conversion, exercise or contingent issuance of the following shares for the following periods because the result would have been antidilutive for the periods indicated. As a result of the anti-dilution, the potential common shares excluded from the diluted EPS computation are as follows: For the year ended December 31, 2017 2016 2015Shares excluded due to anti-dilution (treasury stock method):(In thousands)Potential common shares from: Convertible trust preferred securities (a)1 1 1Total shares excluded due to anti-dilution1 1 1 For the year ended December 31, 2017 2016 2015Shares excluded due to exercise price exceeding the average market price of common shares during the period (total outstanding):(In thousands)Potential common shares from: Options, restricted stock, or other dilutive securities (b)67 270 548Total shares excluded due to exercise price exceeding the average market price of common shares during the period67 270 548(a) If the effect of the conversion of the trust preferred securities would have been dilutive, an immaterial amount of interest expense, net of tax, related to the convertible trust preferred securities would have been added back to net income attributable to common shareholders for the diluted EPS computation for the years presented.(b)Options to purchase shares of common stock, non-participating performance- and certain time-based restricted stock, and other dilutive securities that were outstanding at period ends were not included in the computation of diluted EPS or in the above anti-dilution table because their exercise or conversion prices were greater than the average market price of the common shares during the respective periods.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017	[1]	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income attributable to the Company	$ (18,280)		$ 19,803		$ 23,406		$ 15,662		$ 17,552		$ 19,636		$ 16,398		$ 18,041		$ 40,591	$ 71,628	$ 64,925
Other comprehensive income/ (loss), net of tax:
Unrealized gain/ (loss) on securities available-for-sale																	4,719	(11,358)	(1,349)
Reclassification adjustment for net realized (gain)/ loss included in net income																	(222)	(331)	(139)
Net unrealized gain/ (loss) on securities available-for-sale																	4,497	(11,689)	(1,488)
Unrealized gain/ (loss) on cash flow hedges																	190	(461)	(1,554)
Reclassification adjustment for net realized (gain)/ loss included in net income																	688	979	2,354
Net unrealized gain/ (loss) on cash flow hedges																	878	518	800
Unrealized (gain)/ loss on other																	(50)	(123)	115
Net unrealized gain/ (loss) on other																	(50)	(123)	115
Other comprehensive income/ (loss), net of tax																	5,425	(11,048)	(803)
Total comprehensive income attributable to the Company, net																	$ 46,016	$ 60,580	$ 64,122
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock Including Additional Paid in Capital [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2014	$ 703,911	$ 47,753	$ 82,962	$ 610,903	$ (37,396)	$ (697)	$ 386
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income attributable to the Company	64,925	0	0	0	64,925	0	0
Other comprehensive income/ (loss), net	(803)	0	0	0	0	(803)	0
Dividends paid to common shareholders: $X.XX per share	(29,608)	0	0	(16,703)	(12,905)	0	0
Dividends paid to preferred shareholders	(3,475)	0	0	(1,737)	(1,738)	0	0
Issuance of noncontrolling interests	3,007	0	0	0	0	0	3,007
Net proceeds from issuance of:
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,575	0	138	1,437	0	0	0
Stock Issued under Equity Plans, net of shares forfeited, canceled, or withheld for employee taxes, value	(2,090)	0	161	(2,251)	0	0	0
Amortization of stock compensation and employee stock purchase plan	9,820	0	0	9,820	0	0	0
Stock options exercised	1,206	0	150	1,056	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	(1,262)	0	0	(1,262)	0	0	0
Other equity adjustments	(593)	0	0	(593)	0	0	0
Ending Balance at Dec. 31, 2015	746,613	47,753	83,411	600,670	12,886	(1,500)	3,393
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income attributable to the Company	71,628	0	0	0	71,628	0	0
Other comprehensive income/ (loss), net	(11,048)	0	0	0	0	(11,048)	0
Dividends paid to common shareholders: $X.XX per share	(33,110)	0	0	0	(33,110)	0	0
Dividends paid to preferred shareholders	(3,475)	0	0	0	(3,475)	0	0
Issuance of noncontrolling interests	768	0	0	0	0	0	768
Stock Repurchased During Period, Value	9,323	0	786	8,537	0	0	0
Net proceeds from issuance of:
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,579	0	166	1,413	0	0	0
Stock Issued under Equity Plans, net of shares forfeited, canceled, or withheld for employee taxes, value	(737)	0	193	(930)	0	0	0
Stock Issued During Period, Value, Other	0	0	517	(517)	0	0	0
Amortization of stock compensation and employee stock purchase plan	4,112	0	0	4,112	0	0	0
Stock options exercised	1,725	0	231	1,494	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	(620)	0	0	(620)	0	0	0
Other equity adjustments	369	0	0	369	0	0	0
Ending Balance at Dec. 31, 2016	768,481	47,753	83,732	597,454	47,929	(12,548)	4,161
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net income attributable to the Company	40,591	0	0	0	40,591	0	0
Other comprehensive income/ (loss), net	5,425	0	0	0	0	5,425	0
Dividends paid to common shareholders: $X.XX per share	(37,054)	0	0	0	(37,054)	0	0
Dividends paid to preferred shareholders	(3,475)	0	0	0	(3,475)	0	0
Issuance of noncontrolling interests	1,025	0	0	0	0	0	1,025
Net proceeds from issuance of:
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,601	0	140	1,461	0	0	0
Stock Issued under Equity Plans, net of shares forfeited, canceled, or withheld for employee taxes, value	(1,430)	0	(191)	(1,239)	0	0	0
Stock Issued During Period, Value, Other	3,003	0	419	2,584	0	0	0
Amortization of stock compensation and employee stock purchase plan	8,275	0	0	8,275	0	0	0
Stock options exercised	882	0	108	774	0	0	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0	0	0	0	1,535	(1,535)	0
Other equity adjustments	(1,380)	0	0	(1,380)	0	0	0
Ending Balance at Dec. 31, 2017	$ 785,944	$ 47,753	$ 84,208	$ 607,929	$ 49,526	$ (8,658)	$ 5,186

Consolidated Statement of Shar7

Consolidated Statement of Shareholders' Equity Shareholders' Equity Parenthetical - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Common Stock, Dividends, Per Share, Cash Paid	$ 0.44	$ 0.40	$ 0.36
Common Stock [Member]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.44	$ 0.40	$ 0.36
Stock Issued During Period, Shares, New Issues	140,284	165,934	138,463
Stock Issued During Period, Shares, Share-based Compensation, Gross	0	599,673	738,025
Stock Issued During Period, Shares, Share-based Compensation, Forfeited	(99,927)	(343,929)	(408,638)
Shares of stock withheld for employee taxes	(91,100)	(63,235)	(168,490)
Stock Repurchased During Period, Shares	0	(785,542)	0

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income attributable to the Company	$ 40,591	$ 71,628	$ 64,925
Adjustments to arrive at net income/(loss) from continuing operations
Net income attributable to noncontrolling interests	(4,468)	(4,157)	(4,407)
Net pre-tax gain from operating activities of discontinued operations	8,326	9,452	11,234
Tax expense from discontinued operations	3,456	3,911	4,823
Net income from continuing operations	40,189	70,244	62,921
Adjustments to reconcile net income/(loss) from continuing operations to net cash provided by/(used in) operating activities:
Depreciation and amortization	21,023	23,441	22,187
Net income attributable to noncontrolling interests	(4,468)	(4,157)	(4,407)
Stock compensation, net of cancellations	8,275	4,112	9,820
Impairment of goodwill	24,901	9,528	0
Provision/ (credit) for loan losses	(7,669)	(6,935)	(1,555)
Loans originated for sale	(53,287)	(80,539)	(153,445)
Proceeds from sale of loans held for sale	52,508	85,814	153,679
Gain/ (loss) on sale of affiliates or offices	1,264	(2,862)	0
Deferred income tax expense/ (benefit)	22,845	2,777	(4,575)
Net decrease/(increase) in other operating activities	(8,466)	(817)	2,852
Net cash provided by/(used in) operating activities of continuing operations	97,115	100,606	87,477
Net cash provided by/(used in) operating activities of discontinued operations	4,870	5,541	6,411
Net cash provided by/(used in) operating activities	101,985	106,147	93,888
Investment securities available-for-sale:
Purchases of investment securities available-for-sale	177,021	422,315	506,529
Sales of investment securities available-for-sale	148,407	50,049	34,160
Maturities, redemptions, and principal payments of investment securities available-for-sale	120,546	165,768	208,467
Investment securities held-to-maturity:
Purchases of investment securities held-to-maturity	(14,945)	0	0
Principal payments of investment securities held-to-maturity	32,912	22,522	23,741
(Investments)/distributions in trusts, net	(952)	(508)	(165)
Purchase of additional Bank Owned Life Insurance (BOLI)	50,000	0	0
(Purchase)/ redemption of Federal Home Loan Bank and Federal Reserve Bank stock	(15,896)	(8,896)	(2,900)
Net increase in portfolio loans	(390,003)	(403,670)	(452,675)
Proceeds from recoveries of loans previously charged-off	5,197	10,461	6,253
Proceeds from sale of OREO	1,644	1,337	277
Distributions related to sale of offices	0	(98,517)	0
Capital expenditures, net of sale proceeds	(14,204)	(9,011)	(5,419)
Net cash provided by/(used in) investing activities	(354,315)	(692,780)	(694,790)
Cash flows from financing activities:
Net increase in deposits	425,100	148,303	586,558
Net (decrease)/increase in securities sold under agreements to repurchase and other	(27,455)	1,409	27,719
Net (decrease)/increase in short-term Federal Home Loan Bank borrowings	40,000	310,000	40,000
Net increase/ (decrease) in federal funds purchased	(50,000)	80,000	0
Advances of long-term Federal Home Loan Bank borrowings	50,110	134,779	123,636
Repayments of long-term Federal Home Loan Bank borrowings	(130,634)	(171,898)	(72,462)
Repurchase of common stock	0	(9,323)	0
Dividends paid to common shareholders	(37,054)	(33,110)	(29,608)
Dividends paid to preferred shareholders	(3,475)	(3,475)	(3,475)
Tax benefit/ (deficiency) from certain stock compensation awards	0	(620)	(1,262)
Proceeds from warrant exercises	3,003	0	0
Proceeds from stock option exercises	882	1,725	1,206
Proceeds from issuance of common stock, net	171	842	(515)
Distributions paid to noncontrolling interests	(4,360)	(4,054)	(4,611)
Other equity adjustments	26	(82)	(199)
Net cash provided by/(used in) financing activities	266,314	454,496	666,987
Net increase/(decrease) in cash and cash equivalents	13,984	(132,137)	66,085
Cash and cash equivalents at beginning of year	106,557	238,694	172,609
Cash and cash equivalents at end of period	120,541	106,557	238,694
Supplementary schedule of non-cash investing and financing activities:
Cash paid for interest	33,502	27,415	27,749
Cash paid for income taxes, net of (refunds received)	32,159	33,078	33,318
Change in unrealized gain/ (loss) on securities available-for-sale, net of tax	4,497	(11,689)	(1,488)
Change in unrealized gain/ (loss) on cash flow hedges, net of tax	878	518	800
Change in unrealized gain/ (loss) on other, net of tax	(50)	(123)	115
Transfer of net assets into held for sale	58,034	0	0
Loans charged-off	(863)	(3,949)	(2,036)
Loans transferred into/(out of) other real estate owned from/(to) held for sale or portfolio	0	1,944	0
Reversal of contingent consideration	$ 0	$ 0	$ 2,026

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Boston Private Financial Holdings, Inc. (the “Company” or “BPFH”), is a bank holding company (the “Holding Company”) with four reportable segments: Private Banking, Wealth Management and Trust, Investment Management, and Wealth Advisory. The Private Banking segment is comprised of the banking operations of Boston Private Bank & Trust Company (the “Bank” or “Boston Private Bank”), a trust company chartered by The Commonwealth of Massachusetts, insured by the Federal Deposit Insurance Corporation (the “FDIC”), and a wholly-owned subsidiary of the Company. Boston Private Bank is a member of the Federal Reserve Bank of Boston. Boston Private Bank currently operates in three geographic markets: New England, the San Francisco Bay Area, and Southern California. The Wealth Management and Trust segment is comprised of the operations of Boston Private Wealth LLC (“Boston Private Wealth”), a wholly-owned subsidiary of Boston Private Bank, and the trust operations of Boston Private Bank. The segment offers investment management, wealth management, family office, and trust services to individuals, families, and institutions. The Wealth Management and Trust segment operates in New England; South Florida; California; and Madison, Wisconsin. The Investment Management segment currently has two consolidated affiliates, Dalton, Greiner, Hartman, Maher & Co., LLC (“DGHM”) and Anchor Capital Advisors, LLC (“Anchor”) (together, the “Investment Managers”). In December 2017, the Company entered into an agreement to sell its entire ownership interest in Anchor in a transaction that will result in Anchor being majority-owned by members of its management team. The transaction is expected to close in the first quarter of 2018. This transaction has been approved by the Company’s board of directors and is subject to obtaining client consents, Anchor raising debt financing, and customary closing conditions. The Wealth Advisory segment has two consolidated affiliates, KLS Professional Advisors Group, LLC (“KLS”) and Bingham, Osborn & Scarborough, LLC (“BOS”) (together, the “Wealth Advisors” and, together with the Wealth Management and Trust and Investment Management segments, the “Wealth and Investment” businesses). Basis of Presentation The consolidated financial statements of the Company include the accounts of the Company and its wholly-owned and majority-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation, and the portion of income allocated to owners other than the Company is included in “Net income attributable to noncontrolling interests” in the consolidated statements of operations. Redeemable noncontrolling interests in the consolidated balance sheets reflect the maximum redemption value of agreements with other owners. All accounts related to divested affiliates are included within the results of discontinued operations for all periods presented. The financial statements are prepared in accordance with accounting principles generally accepted in the United States (“U.S.”) (“GAAP”). Reclassifications of amounts in prior years’ consolidated financial statements are made whenever necessary to conform to the current year’s presentation. Use of Estimates In preparing the consolidated financial statements, management is required to make certain estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and revenues and expenses for the period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to change, in the near term, relate to the determination of the allowance for loan losses, evaluation of potential impairment of goodwill and other intangibles, and income tax estimates. Significant Group Concentrations of Credit Risk Most of the Company’s activities are with clients within the New England, the San Francisco Bay Area, and Southern California regions of the country. The Company does not believe it has any significant concentrations in any one industry, geographic location, or with any one client. Part II. Item 8. “Financial Statements and Supplementary Data - Note 4: Investment Securities,” highlights the types of securities in which the Company invests, and Part II. Item 8. “Financial Statements and Supplementary Data - Note 5: Loan Portfolio and Credit Quality,” describes the concentration of the Private Banking loan data based on the location of the lender. Statement of Cash Flows For purposes of reporting cash flows, the Company considers cash and due from banks which have original maturities with 90 days or less to be cash equivalents. Cash and Due from Banks The Bank is required to maintain average reserve balances in an account with the Federal Reserve based upon a percentage of certain deposits. As of December 31, 2017 and 2016 , the daily amounts required to be held in the aggregate for the Bank were $3.6 million and $5.0 million , respectively. Investment Securities Available-for-sale investment securities are reported at fair value, with unrealized gains and losses credited or charged, net of the estimated tax effect, to accumulated other comprehensive income/ (loss). Held-to-maturity investment securities are those which the Company has the positive intent and ability to hold to maturity and are reported at amortized cost. Premiums and discounts on the investment securities are amortized or accreted into net interest income by the level-yield method. Gains and losses on the sale of the available-for-sale investments are recognized at the trade date on a specific identification basis. Dividend and interest income is recognized when earned and is recorded on the accrual basis. The Company conducts a quarterly review and evaluation of its investment securities to determine if the decline in fair value of a security below its amortized cost is deemed to be other-than-temporary. Other-than-temporary impairment losses are recognized on securities when: (i) the holder has an intention to sell the security; (ii) it is more likely than not that the security will be required to be sold prior to recovery; or (iii) the holder does not expect to recover the entire amortized cost basis of the security. Other-than-temporary losses are reflected in earnings as a charge against gain on sale of investments, net, to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in accumulated other comprehensive income/ (loss). The Company has no intention to sell any securities in an unrealized loss position at December 31, 2017 nor is it more likely than not that the Company would be required to sell such securities prior to the recovery of the unrealized losses. As of December 31, 2017 , the Company believes that all impairments of investment securities are temporary in nature. No other-than-temporary impairment losses were recognized in the consolidated statements of operations for the years ended December 31, 2017 , 2016 , and 2015 . Loans Held for Sale Loans originated and held for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Fair value is based on commitments on hand from investors or prevailing market prices. Unrealized losses, if any, are recognized through a valuation allowance by charges to income. Loans transferred to the held for sale category from the loan portfolio are transferred at the lower of cost or fair value, usually as determined at the individual loan level. If fair value is less than cost, then a charge for the difference will be made to the allowance for loan losses if the decline in value is due to credit issues. Gains or losses on the sale of loans are recognized at the time of sale on a specific identification basis. Interest income is recognized on an accrual basis when earned. Loans Loans are carried at the principal amount outstanding, net of participations, deferred loan origination fees and costs, charge-offs, and interest payments applied to principal on nonaccrual loans. Loan origination fees, net of related direct incremental loan origination costs, are deferred and recognized into income over the contractual lives of the related loans as an adjustment to the loan yield, using the level-yield method. If a loan is paid off prior to maturity, the unamortized portion of net fees/cost is recognized into interest income. If a loan is sold, the unamortized portion of net fees/cost is recognized at the time of sale as a component of the gain or loss on sale of loans. When the Company analyzes its loan portfolio to determine the adequacy of its allowance for loan losses, it categorizes the loans by portfolio segment and class of financing receivable based on the similarities in risk characteristics for the loans. The Company has determined that its portfolio segments and classes of financing receivables are one and the same, with the exception of the commercial and industrial portfolio segment, which consists of other commercial and industrial loans and commercial tax-exempt loans. The level at which the Company develops and documents its allowance for loan loss methodology is consistent with the grouping of financing receivables based upon initial measurement attributes, risk characteristics, and the Company’s method for monitoring and assessing credit risks. These portfolio segments and classes of financing receivables are: • Commercial and industrial (portfolio segment) ◦ Other commercial and industrial loans (class of financing receivable) - Commercial and industrial loans include working capital and revolving lines of credit, term loans for equipment and fixed assets, and Small Business Administration (“SBA”) loans. ◦ Commercial tax-exempt loans (class of financing receivable) - Commercial tax-exempt loans include loans to not-for-profit private schools, colleges, and public charter schools. • Commercial real estate (segment and class) - Commercial real estate loans are generally acquisition financing for commercial properties such as office buildings, retail properties, apartment buildings, and industrial/warehouse space. In addition, tax-exempt commercial real estate loans are provided for affordable housing development and rehabilitation. These loans are often supplemented with federal, state, and/or local subsidies. • Construction and land (segment and class) - Construction and land loans include loans for financing of new developments as well as financing for improvements to existing buildings. In addition, tax-exempt construction and land loans are provided for the construction phase of the commercial tax-exempt and commercial real estate tax-exempt loans described above. • Residential mortgage (segment and class) - Residential mortgage loans consist of loans secured by single-family and one- to four-unit properties in excess of the amount eligible for purchase by the Federal National Mortgage Association, which was $424 thousand at December 31, 2017 for the “General” limit and $636 thousand for single-family properties for the “High-Cost” limit, depending on which specific geographic region of the Bank’s primary market areas the loan was originated. While the Bank has no minimum size for mortgage loans, it concentrates its origination activities in the “Jumbo” segment of the market. • Home equity (segment and class) - Home equity loans consist of balances outstanding on second mortgages and home equity lines of credit extended to individual clients. Personal lines of credit are typically for high net worth clients whose assets may not be liquid due to investments or closely held stock. The amount of home equity loans typically depends on client demand. • Consumer and other (segment and class) - Consumer and other loans consist of balances outstanding on consumer loans including personal lines of credit, and loans arising from overdraft protection extended to individual and business clients. Personal lines of credit are typically for high net worth clients whose assets may not be liquid due to investments or closely held stock. The amount of consumer and other loans typically depends on client demand. The past due status of a loan is determined in accordance with its contractual repayment terms. All portfolio segments are reported past due when one scheduled payment is due and unpaid for 30 days or more. The Bank’s policy is to discontinue the accrual of interest on a loan when the collectability of principal or interest is in doubt. When management determines that it is probable that the Bank will not collect all principal and interest on a loan in accordance with the original loan terms, the loan is designated as impaired. Impaired loans are usually commercial loans or construction and land loans, for which it is probable that the Company will not collect all amounts due according to the contractual terms of the loan agreement, and all loans restructured in a troubled debt restructuring. Accrual of interest income is discontinued and all interest previously accrued but not collected is reversed against current period interest income when a loan is initially classified as nonaccrual. Generally, interest received on nonaccrual loans is applied against principal or, on a limited basis, reported as interest income on a cash basis, when according to management’s judgment, the collectability of principal is reasonably assured. The Bank’s general policy for returning a loan to accrual status requires the loan to be brought current, for the client to show a history of making timely payments (generally six consecutive months), and when the financial position of the borrower and other relevant factors indicate there is no longer doubt as to the collectability of the loan. The Bank’s loan commitments are generally short-term in nature with terms that are primarily variable. Given the limited interest rate exposure posed by the commitments, the Bank estimates the fair value of these commitments to be immaterial. Credit Quality Indicators The Bank uses a risk rating system to monitor the credit quality of its loan portfolio. Loan classifications are assessments made by the Bank of the status of the loans based on the facts and circumstances known to the Bank, including management’s judgment, at the time of assessment. Some or all of these classifications may change in the future if there are unexpected changes in the financial condition of the borrower, including but not limited to, changes resulting from continuing deterioration in general economic conditions on a national basis or in the local markets in which the Bank operates adversely affecting, among other things, real estate values. Such conditions, as well as other factors which adversely affect borrowers’ ability to service or repay loans, typically result in changes in loan default and charge-off rates, and increased provisions for loan losses, which would adversely affect the Company’s financial performance and financial condition. These circumstances are not entirely foreseeable and, as a result, it may not be possible to accurately reflect them in the Company’s analysis of credit risk. Generally, only commercial loans, including commercial real estate, other commercial and industrial loans, commercial tax-exempt loans, and construction and land loans, are given a numerical grade. A summary of the rating system used by the Bank follows: Pass - All loans graded as pass are considered acceptable credit quality by the Bank and are grouped for purposes of calculating the allowance for loan losses. For residential, home equity, and consumer loans, the Bank classifies loans as pass unless there is known information such as delinquency or client requests for modifications which, due to financial difficulty, would then generally result in a risk rating such as special mention or more severe depending on the factors. Special Mention - Loans rated in this category are defined as having potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may, at some future date, result in the deterioration of the repayment prospects for the credit or the Bank’s credit position. These loans are currently protected but have the potential to deteriorate to a substandard rating. For commercial loans, the borrower’s financial performance may be inconsistent or below forecast, creating the possibility of liquidity problems and shrinking debt service coverage. In loans having this rating, the primary source of repayment is still good, but there is increasing reliance on collateral or guarantor support. Collectability of the loan is not yet in jeopardy. In particular, loans in this category are considered more variable than other categories, since they will typically migrate through categories more quickly. Substandard - Loans rated in this category are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. A substandard credit has a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected. Substandard loans may be either still accruing or nonaccruing depending upon the severity of the risk and other factors such as the value of the collateral, if any, and past due status. Doubtful - Loans rated in this category indicate that collection or liquidation in full on the basis of currently existing facts, conditions, and values, is highly questionable and improbable. Loans in this category are usually on nonaccrual and classified as impaired. Restructured Loans When the Bank, for economic or legal reasons related to a borrower’s financial difficulties, grants a concession to a troubled borrower that it would not otherwise consider, the loan is classified as a restructured loan pursuant to Accounting Standards Codification (“ASC”) 470, Debt . The concession either stems from an agreement between the creditor and the Bank or is imposed by law or a court. The concessions may include: • Deferral of principal and/or interest payments • Lower interest rate as compared to a new loan with comparable risk and terms • Extension of the maturity date • Reduction in the principal balance owed All loans whose terms have been modified in a troubled debt restructuring, including commercial, residential, and consumer, are evaluated for impairment under ASC 310, Receivables . Generally, a nonaccrual loan that is restructured remains on nonaccrual status for a period of at least six months to demonstrate that the borrower can meet the restructured terms. However, performance prior to the restructuring, or significant events that coincide with the restructuring, are considered when assessing whether the borrower can meet the new terms and may result in the loan being returned to accrual status at the time of the restructuring or after a shorter performance period. If the borrower’s ability to meet the revised payment schedule is uncertain, the loan remains classified as a nonaccrual loan. A loan may be removed from a restructured classification after the next fiscal year end, if the restructured terms include a market interest rate and the borrower has demonstrated performance with the restructured terms. Allowance for Loan and Lease Losses The allowance for loan losses (“allowance”) is an estimate of the inherent risk of loss in the loan portfolio as of the consolidated balance sheet dates. Management estimates the level of the allowance based on all relevant information available. Changes to the required level in the allowance result in either a provision for loan loss expense, if an increase is required, or a credit to the provision, if a decrease is required. Loan losses are charged to the allowance when available information confirms that specific loans, or portions thereof, are uncollectible. Recoveries on loans previously charged-off are credited to the allowance when received in cash. The Company’s allowance is accounted for in accordance with guidance issued by various regulatory agencies, including: the Federal Financial Institutions Examination Council Policy Statement on the Allowance for Loan and Lease Losses (December 2006); Securities and Exchange Commission (“SEC”) Staff Accounting Bulletin No. 102, Selected Loan Loss Methodology and Documentation Issues ; ASC 310; and ASC 450, Contingencies . The allowance consists of three primary components: general reserves on pass graded loans, allocated reserves on non-impaired special mention and substandard loans, and the specific reserves on impaired loans. The calculation of the allowance involves a high degree of management judgment and estimates designed to reflect the inherent risk of loss in the loan portfolio at the measurement date. General reserves are calculated for each loan pool consisting of pass graded loans segregated by portfolio segment, by applying estimated net loss percentages based upon the Bank’s actual historical net charge-offs and, adjusted as appropriate, on a consistent manner based upon consideration of qualitative factors to arrive at a total loss factor for each portfolio segment. The rationale for qualitative adjustments is to more accurately reflect the current inherent risk of loss in the respective portfolio segments than would be determined through the sole consideration of the Bank’s actual historical net charge-off rates. The numerical factors assigned to each qualitative factor are based upon observable data, if applicable, as well as management’s analysis and judgment. The qualitative factors considered by the Company include: • Volume and severity of past due, nonaccrual, and adversely graded loans, • Volume and terms of loans, • Concentrations of credit, • Management’s experience, as well as loan underwriting and loan review policy and procedures, • Economic and business conditions impacting the Bank’s loan portfolio, as well as consideration of collateral values, and • External factors, including consideration of loss factor trends, competition, and legal and regulatory requirements. The Bank makes a determination of the applicable loss rate for these factors based on relevant local market conditions, credit quality, and portfolio mix. Each quarter, management reviews the loss factors to determine if there have been any changes in its loan portfolio, market conditions, or other risk indicators which would result in a change to the current loss factor. Allocated reserves on non-impaired special mention and substandard loans reflect management’s assessment of increased risk of losses associated with these types of adversely graded loans. An allocated reserve is assigned to these pools of loans based upon management’s consideration of the credit attributes of individual loans within each pool of loans, including consideration of loan to value ratios, past due status, strength and willingness of the guarantors, and other relevant attributes, as well as the qualitative factors considered for the general reserve as discussed above. These considerations are determined separately for each type of portfolio segment. The allocated reserves are a multiple of the general reserve for each respective portfolio segments, with a greater multiple for loans with increased risk ( i.e. , special mention loans versus substandard loans). A loan is considered impaired in accordance with ASC 310 when, based upon current information and events, it is probable that a creditor will be unable to collect all amounts due according to the contractual terms of the loan agreement. Impairment is measured based on the fair value of the loan, expected future cash flows discounted at the loan’s effective interest rate, or as a practical expedient, impairment may be determined based upon the observable market price of the loan, or the fair value of the collateral, less estimated costs to sell, if the loan is “collateral dependent.” A loan is collateral dependent if repayment of the loan is expected to be provided solely by the underlying collateral or sale of the underlying collateral. For collateral dependent loans, appraisals are generally used to determine the fair value. When a collateral dependent loan becomes impaired, an updated appraisal of the collateral is obtained, if appropriate. Appraised values are generally discounted for factors such as the Bank’s intention to liquidate the property quickly in a foreclosure sale or the date when the appraisal was performed if the Bank believes that collateral values have declined since the date the appraisal was done. The Bank may use a broker opinion of value in addition to an appraisal to validate the appraised value. In certain instances, the Bank may consider broker opinions of value as well as other qualitative factors while an appraisal is being prepared. If the loan is deemed to be collateral dependent, generally the difference between the book balance (client balance less any prior charge-offs or client interest payments applied to principal) and the fair value of the collateral is taken as a partial charge-off through the allowance for loan losses in the current period. If the loan is not determined to be collateral dependent, then a specific allocation to the general reserve is established for the difference between the book balance of the loan and the expected future cash flows discounted at the loan’s effective interest rate. Charge-offs for loans not considered to be collateral dependent are made when it is determined a loss has been incurred. Impaired loans are removed from the general loan pools. There may be instances where the loan is considered impaired although based on the fair value of underlying collateral or the discounted expected future cash flows there is no impairment to be recognized. In addition, all loans which are classified as troubled debt restructurings (“TDRs”) are considered impaired. In addition to the three primary components of the allowance for loan losses discussed above (general reserve, allocated reserves on non-impaired special mention and substandard loans, and the specific reserves on impaired loans), the Bank may also maintain an insignificant amount of additional allowance for loan losses (the unallocated allowance for loan losses). The unallocated reserve reflects the fact that the allowance for loan losses is an estimate and contains a certain amount of imprecision risk. It represents risks identified by Management that are not already captured in the qualitative factors discussed above. The unallocated allowance for loan losses is not considered significant by the Company and will remain at zero unless additional risk is identified. While this evaluation process utilizes historical and other objective information, the classification of loans and the establishment of the allowance for loan losses rely to a great extent on the judgment and experience of management. While management evaluates currently available information in establishing the allowance for loan losses, future adjustments to the allowance may be necessary if economic conditions differ substantially from the assumptions used in making the evaluations. In addition, various regulatory agencies, as an integral part of their examination process, periodically review a financial institution’s allowance for loan losses as well as loan grades/classifications. Such agencies may require the financial institution to recognize additions to the allowance for loan losses or increases to adversely graded loans based on their judgments about information available to them at the time of their examination. Reserve for Unfunded Loan Commitments The Company maintains a reserve for unfunded loan commitments for such items as unused portion of lines of credit and unadvanced construction loans. The reserve is maintained at a level that reflects the risk in these various commitments. Management determines the reserve percentages on a quarterly basis based on a percentage of the current historical loss rates for these portfolios. Once a loan commitment is funded, the reserve for unfunded loan commitment is reversed and a corresponding allowance for loan loss reserve is established. This unfunded loan commitment reserve is included in other liabilities in the consolidated balance sheets. Net adjustments to the reserve for unfunded commitments are included in other operating expense in the consolidated statements of operations. Other Real Estate Owned (“OREO”) OREO is comprised of property acquired through foreclosure proceedings or acceptance of a deed-in-lieu of foreclosure in partial or total satisfaction of certain loans. Properties are recorded at the lower of the recorded investment in the loan at the time of acquisition or the fair value, as established by a current appraisal, comparable sales, and other estimates of value obtained principally from independent sources, less estimated costs to sell. Any decline in fair value compared to the carrying value of a property at the time of acquisition is charged against the allowance for loan losses. Any subsequent valuation adjustments to reflect declines in current fair value, as well as gains or losses on disposition are reported in gain/(loss) on OREO, net in the consolidated statements of operations. Expenses incurred for holding or maintaining OREO properties such as real estate taxes, utilities, and insurance are charged as incurred to other operating expenses in the consolidated statements of operations. Rental income earned, although generally minimal, is offset against other operating expenses. Premises and Equipment Premises and equipment consists of leasehold improvements, furniture, fixtures, equipment, art, buildings, and land. Equipment consists primarily of computer equipment. Premises and equipment are carried at cost, less accumulated depreciation and amortization. Also included in premises and equipment is technology initiatives in process. Depreciation and amortization are computed primarily by the straight-line method over the estimated useful lives of the assets, or the terms of the leases, if shorter, for leasehold improvements. The estimated useful lives for leasehold improvements and buildings are 5-15 years and 40 years, respectively. The estimated useful life for furniture and fixtures is 2-10 years and is 3-5 years for computer equipment. The costs of improvements that extend the life of an asset are capitalized, while the cost of repairs and maintenance are expensed as incurred. Neither land nor art is depreciated. Valuation of Goodwill/Intangible Assets and Analysis for Impairment The Company allocates the cost of an acquired entity to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Other intangible assets identified in acquisitions generally consist of advisory contracts, trade names, and non-compete agreements. The value attributed to advisory contracts is based on the time period over which they are expected to generate economic benefits. The advisory contracts are generally amortized over 8-15 years, depending on the contract. Trade names are not amortized. Long-lived intangible assets are subject to the impairment provisions of ASC 360-10, Property, Plant, and Equipment (“ASC 360”). Long-lived intangible assets are tested for recoverability by comparing the net carrying value of the asset or asset group to the undiscounted net cash flows to be generated from the use and eventual disposition of that asset (asset group) when events or changes in circumstances indicate that its carrying amount may not be recoverable. If the carrying amount of the asset exceeds its net undiscounted cash flows, then an impairment loss is recognized for the amount by which the carrying amount exceeds its fair value, determined based upon the discounted value of the expected cash flows generated by the asset. The intangible impairment test is performed at the reporting unit level, and each affiliate with goodwill and/or intangible assets is considered a reporting unit for goodwill and intangible impairment testing purposes. The excess of the purchase price for acquisitions over the fair value of the net assets acquired, including other intangible assets, is recorded as goodwill. Goodwill is not amortized but is tested for impairment at the reporting unit level, defined as the affiliate level, at least annually in the fourth quarter or more frequently when events or circumstances occ

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	RESTRUCTURING In the fourth quarter of 2014, the Company incurred restructuring charges related to the acquisition of Banyan Partners, LLC (“Banyan”). The purpose of this restructuring was to realign the management structure within the Wealth Management and Trust segment. The total cost of the restructuring incurred in the fourth quarter of 2014 was $0.7 million . In 2015, the Company incurred additional restructuring charges to further refine the management structure within the Wealth Management and Trust segment. The total cost of the restructuring charges in 2015 was $3.7 million . In the first and second quarters of 2016, the Company incurred additional costs of $1.1 million and $0.9 million , respectively, in the continued refinement of the management structure within the Wealth Management and Trust segment. The Company does not anticipate any additional restructuring costs related to this plan as of the date of this filing. Restructuring expenses incurred since the plans of restructuring were first implemented in 2014 totaled $6.4 million , all within the Wealth Management and Trust segment. The following table presents a summary of the restructuring activity for the years ended December 31, 2017, 2016 and 2015. Severance Charges Other Associated Costs Total (In thousands) Accrued charges at December 31, 2014 $ 739 $ — $ 739 Costs incurred 3,434 290 3,724 Costs paid (868 ) (290 ) (1,158 ) Accrued charges at December 31, 2015 3,305 — 3,305 Costs incurred 2,017 — 2,017 Costs paid (3,345 ) — (3,345 ) Accrued charges at December 31, 2016 1,977 — 1,977 Costs incurred — — — Costs paid (1,640 ) — (1,640 ) Accrued charges at December 31, 2017 $ 337 $ — $ 337

Acquisitions, Asset Sales, and

Acquisitions, Asset Sales, and Divestitures	12 Months Ended
	Dec. 31, 2017
DIVESTITURES AND ACQUISITIONS [Abstract]
Discontinued Operations and Business Combinations Disclosure [Text Block]	ACQUISITIONS, ASSET SALES, AND DIVESTITURES Asset Sales In December 2017, the Company entered into an agreement to sell its entire ownership interest in Anchor in a transaction that will result in Anchor being majority-owned by members of its management team. The Company will receive approximately $32 million of cash at closing and future revenue share payments that, at signing, had a net present value of approximately $15 million , subject to purchase price adjustments. The Company’s annual goodwill impairment test for Anchor resulted in a fourth quarter of 2017 goodwill impairment charge of $24.9 million . Anchor’s $58.8 million of assets and $3.2 million of liabilities have been classified as held for sale at December 31, 2017. The Company also recorded a loss on sale of $1.3 million representing estimated closing costs upon completion of the sale. Income tax expense of approximately $11.4 million will be recorded at the time of the closing of the transaction as a result of a book to tax basis difference associated with nondeductible goodwill. The estimated loss on sale as well as the income tax expense could change depending upon the book value of Anchor at the time of closing. The transaction is expected to close in the first quarter of 2018. This transaction has been approved by the Company’s board of directors and is subject to obtaining client consents, Anchor raising debt financing, and customary closing conditions. The rationale for the sale is to focus the Company’s resources in businesses where we can offer holistic financial advice, along with integrated wealth management, trust, and private banking capabilities. This transaction will also generate additional capital for us to reinvest in a more focused Company. In 2016, the Company sold two offices in the Southern California market, located in Granada Hills and Burbank, California. The sale consisted of certain assets and $104.0 million of deposits. This sale resulted in a gain of $2.9 million . The rationale for the sale was to better position the Company’s resources within the Southern California market. Acquisitions On October 2, 2014 , the Bank completed the acquisition of Banyan, a registered investment advisory firm headquartered in Palm Beach Gardens, Florida. At the time of acquisition, Banyan had approximately $4.3 billion in client assets and locations in New England; South Florida; Texas; California; Atlanta, Georgia; and Madison, Wisconsin. In the transaction, Boston Private Bank acquired 100% of certain assets and liabilities of Banyan through the issuance of approximately 1.7 million shares of the Company’s stock, valued at $21.0 million , and $43.9 million in cash payments to Banyan shareholders, including $5.0 million in a holdback account for potential future claims. The total purchase price, including contingent consideration of $2.0 million , was $66.9 million . In 2015, due to the lower than initially estimated actual financial results for 2015 and projected financial results for 2016, the $2.0 million liability for the contingent consideration was reversed and recorded as Other Income. 2016 was the last year of any contingent consideration and the contractual minimum targets for contingent payments were not met. Goodwill of $41.9 million was recorded as a result of the transaction. Goodwill of $39.9 million is deductible for tax purposes, representing all of the goodwill except for the portion associated with the reversal of the contingent consideration. Intangible assets for advisory contracts of $23.9 million were also recorded and are expected to be amortized over 10 years . The rationale for the transaction was that by merging Banyan with the existing Boston Private Bank wealth management business, additional technical expertise and financial acumen would be generated. Banyan has been merged with the existing wealth management business from Boston Private Bank, and the combined company has been renamed Boston Private Wealth. As a wholly-owned subsidiary of the Bank, Boston Private Wealth will also operate as part of the Wealth Management and Trust segment along with the trust operations of the Bank. These operations are reported separately from the Private Banking operations of the Bank. Divestitures In 2009, the Company divested its interests in Westfield Capital Management Company, LP, formerly known as Westfield Capital Management Company, LLC (“Westfield”). The Company retained a 12.5% share in Westfield’s revenues (up to an annual maximum of $11.6 million) through December 2017 subject to certain conditions. The Company defers gains related to these payments until determinable. Such revenue share payments are included in net income from discontinued operations in the consolidated statements of operations for the period in which the revenue is recognized. After the December 2017 payments are received in the first quarter of 2018, the Company will not receive additional net income from Westfield.

Investments

Investments	12 Months Ended
	Dec. 31, 2017
Investments [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	INVESTMENT SECURITIES The following tables present a summary of investment securities: Amortized Cost Unrealized Fair Value Gains Losses (In thousands) At December 31, 2017: Available-for-sale securities at fair value: U.S. government and agencies $ 35,132 $ — $ (833 ) $ 34,299 Government-sponsored entities 305,101 22 (2,622 ) 302,501 Municipal bonds 299,647 4,559 (1,148 ) 303,058 Mortgage-backed securities (1) 521,753 491 (12,568 ) 509,676 Other 20,794 — — 20,794 Total $ 1,182,427 $ 5,072 $ (17,171 ) $ 1,170,328 Held-to-maturity securities at amortized cost: Mortgage-backed securities (1) $ 74,576 $ — $ (795 ) $ 73,781 Total $ 74,576 $ — $ (795 ) $ 73,781 Amortized Cost Unrealized Fair Value Gains Losses (In thousands) At December 31, 2016: Available-for-sale securities at fair value: U.S. government and agencies $ 40,704 $ 86 $ (854 ) $ 39,936 Government-sponsored entities 337,865 1,058 (2,259 ) 336,664 Municipal bonds 296,271 2,116 (4,990 ) 293,397 Mortgage-backed securities (1) 584,960 928 (15,561 ) 570,327 Other 23,361 447 — 23,808 Total $ 1,283,161 $ 4,635 $ (23,664 ) $ 1,264,132 Held-to-maturity securities at amortized cost: Mortgage-backed securities (1) $ 93,079 $ 1 $ (476 ) $ 92,604 Total $ 93,079 $ 1 $ (476 ) $ 92,604 _________________ (1) All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities. In the tables below, the weighted average yield is calculated based on average amortized cost which does not include the effect of unrealized changes in fair value. Certain securities are callable before their final maturity. Additionally, certain securities (such as mortgage-backed securities) are shown within the table below based on their final (contractual) maturity, but, due to prepayments, are expected to have shorter lives. The following tables present the maturities of available-for-sale investment securities, based on contractual maturity, and the weighted average yields of such securities as of December 31, 2017 : U.S. government and agencies (1) Government-sponsored entities (1) Amortized cost Fair value Weighted average yield Amortized cost Fair value Weighted average yield (In thousands) Within one year $ — $ — — % $ 44,033 $ 43,967 1.39 % After one, but within five years 15,192 15,105 1.53 % 224,747 223,315 1.86 % After five, but within ten years 19,940 19,194 1.73 % 36,321 35,219 2.05 % Greater than ten years — — — % — — — % Total $ 35,132 $ 34,299 1.64 % $ 305,101 $ 302,501 1.81 % Municipal bonds (1) Mortgage-backed securities (2) Amortized cost Fair value Weighted average yield (3) Amortized cost Fair value Weighted average yield (In thousands) Within one year $ 15,770 $ 15,756 1.85 % $ 17 $ 17 2.33 % After one, but within five years 57,178 57,260 2.63 % 11,460 11,407 2.25 % After five, but within ten years 33,979 34,719 3.73 % 236,360 229,770 2.18 % Greater than ten years 192,720 195,323 4.07 % 273,916 268,482 2.10 % Total $ 299,647 $ 303,058 3.64 % $ 521,753 $ 509,676 2.14 % Other (4) Amortized cost Fair value Weighted average yield (In thousands) Within one year $ 20,794 $ 20,794 — % After one, but within five years — — — % After five, but within ten years — — — % Greater than ten years — — — % Total $ 20,794 $ 20,794 — % The following table presents the maturities of held-to-maturity investment securities, based on contractual maturity, and the weighted average yields of such securities as of December 31, 2017 : Mortgage-backed securities (2) Amortized cost Fair value Weighted average yield (In thousands) Within one year $ — $ — — % After one, but within five years — — — % After five, but within ten years 16,722 16,551 2.17 % Greater than ten years 57,854 57,230 2.30 % Total $ 74,576 $ 73,781 2.27 % ___________________ (1) Certain securities are callable before their final maturity. (2) Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives. (3) Yields shown on a fully taxable equivalent (“FTE”) basis. The tax rate used in the table above was the tax rate in effect on December 31, 2017. The recent enactment of the Tax Act will reduce the rate applied in future periods, which will result in a lower FTE yield. (4) Other securities consist of money market mutual funds and equity securities held by certain Wealth Advisory and Investment Management businesses. The weighted average remaining maturity at December 31, 2017 was 8.1 years for available-for-sale investment securities, with $184.9 million of available-for-sale investment securities callable before maturity. The weighted average remaining maturity at December 31, 2016 was 9.1 years for available-for-sale investment securities, with $140.4 million of available-for-sale investment securities callable before maturity. The weighted average remaining maturity for held-to-maturity investment securities was 11.9 years and 12.9 years at December 31, 2017 and December 31, 2016 , respectively. The following table presents the proceeds from sales, gross realized gains and gross realized losses for available-for-sale investment securities that were sold during the following years: Year Ended December 31, 2017 2016 2015 (In thousands) Proceeds from sales $ 148,407 $ 50,049 $ 34,160 Realized gains 519 522 272 Realized losses (143 ) (1 ) (36 ) The following tables present information regarding securities at December 31, 2017 and 2016 having temporary impairment, due to the fair values having declined below the amortized cost of the individual securities, and the time period that the investments have been temporarily impaired. Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses # of securities (In thousands, except number of securities) December 31, 2017 Available-for-sale securities U.S. government and agencies $ 14,902 $ (79 ) $ 19,397 $ (754 ) $ 34,299 $ (833 ) 6 Government-sponsored entities 220,275 (1,350 ) 38,273 (1,272 ) 258,548 (2,622 ) 36 Municipal bonds 46,112 (131 ) 50,842 (1,017 ) 96,954 (1,148 ) 63 Mortgage-backed securities (1) 97,117 (903 ) 386,785 (11,665 ) 483,902 (12,568 ) 103 Total $ 378,406 $ (2,463 ) $ 495,297 $ (14,708 ) $ 873,703 $ (17,171 ) 208 Held-to-maturity securities Mortgage-backed securities (1) $ 59,218 $ (534 ) $ 14,563 $ (261 ) $ 73,781 $ (795 ) 16 Total $ 59,218 $ (534 ) $ 14,563 $ (261 ) $ 73,781 $ (795 ) 16 Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses # of securities (In thousands, except number of securities) December 31, 2016 Available-for-sale securities U.S. government and agencies $ 19,094 $ (838 ) $ 643 $ (16 ) $ 19,737 $ (854 ) 4 Government-sponsored entities 125,412 (2,259 ) — — 125,412 (2,259 ) 18 Municipal bonds 182,395 (4,957 ) 2,720 (33 ) 185,115 (4,990 ) 109 Mortgage-backed securities (1) 492,008 (13,988 ) 41,544 (1,573 ) 533,552 (15,561 ) 99 Total $ 818,909 $ (22,042 ) $ 44,907 $ (1,622 ) $ 863,816 $ (23,664 ) 230 Held-to-maturity securities Mortgage-backed securities (1) $ 87,483 $ (476 ) $ — $ — $ 87,483 $ (476 ) 15 Total $ 87,483 $ (476 ) $ — $ — $ 87,483 $ (476 ) 15 ___________________ (1) All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities. As of December 31, 2017 , the U.S. government and agencies securities and government-sponsored entities securities in the first table above had current Moody’s credit ratings of Aaa. The mortgage-backed securities in the first table above had a current Standard and Poor’s credit rating of at least AA. The municipal bonds in the first table above had a current Standard and Poor’s credit rating of at least AA- or a current Moody’s credit rating of at least Aa3. The other securities in the first table above consisted of equity securities. At December 31, 2017 , the Company does not consider these investments other-than-temporarily impaired because the decline in fair value on investments is primarily attributed to changes in interest rates and not credit quality. At December 31, 2017 and December 31, 2016 , the amount of investment securities in an unrealized loss position greater than 12 months, as well as in total, was primarily due to changes in interest rates. As of December 31, 2017 , the Company had no intent to sell any securities in an unrealized loss position and it is not more likely than not that the Company would be forced to sell any of these securities prior to the full recovery of all unrealized loss amounts. Subsequent to December 31, 2017 and through the date of the filing of this Annual Report on Form 10-K, no securities were downgraded to below investment grade, nor were any securities in an unrealized loss position sold. The following table presents the concentration of securities with any one issuer that exceeds ten percent of shareholders’ equity as of December 31, 2017 : Amortized cost Fair value (In thousands) Government National Mortgage Association $ 104,188 $ 101,941 Federal Home Loan Mortgage Corporation 349,926 342,374 Federal Home Loan Bank 163,151 161,747 Federal National Mortgage Association 259,108 255,143 Total $ 876,373 $ 861,205 Cost method investments The Company invests in low-income housing tax credits, which are included in other assets, to encourage private capital investment in the construction and rehabilitation of low-income housing. The Company makes these investments as an indirect subsidy that allows investors, such as the Company, in a flow-through limited liability entity, such as limited partnerships or limited liability companies that manage or invest in qualified affordable housing projects, to receive the benefits of the tax credits allocated to the entity that owns the qualified affordable housing project. The Company also holds partnership interests in venture capital funds formed to provide financing to small businesses and to promote community development. The Company amortizes its investment in the low income housing tax credits using the proportional amortization method. Under the proportional amortization method, the Company amortizes the cost of its investment, in proportion to the tax credits and other tax benefits it receives to income tax expense. Included in income tax expense was amortization of $2.7 million , $1.6 million , and $1.3 million for the years ending December 31, 2017, 2016 and 2015, respectively. Also included in income tax expense were the related tax benefits of $2.2 million , $1.7 million and $1.3 million for the years ending December 31, 2017, 2016, and 2015, respectively. The Company had $39.4 million and $34.2 million in cost method investments included in other assets as of December 31, 2017 and December 31, 2016 , respectively. In addition the Company had $11.5 million and $11.3 million in unadvanced funds related to commitments in these investments as of December 31, 2017 and 2016, respectively. Under the proportional amortization method, an investment must be tested for impairment when events or changes in circumstances indicate that it is more likely than not that the carrying amount of the investment will not be realized. There was no indication of impairment for the years ending December 31, 2017 and 2016.

Loans Receivable and Credit Qua

Loans Receivable and Credit Quality	12 Months Ended
	Dec. 31, 2017
Loans Receivable [Abstract]
Financing Receivables [Text Block]	LOAN PORTFOLIO AND CREDIT QUALITY The Bank’s lending activities are conducted principally in the regions of New England, the San Francisco Bay Area, and Southern California. The Bank originates single and multi-family residential loans, commercial real estate loans, commercial and industrial loans, commercial tax-exempt loans, construction and land loans, and home equity and other consumer loans. Most loans are secured by borrowers’ personal or business assets. The ability of the Bank’s single family residential and consumer borrowers to honor their repayment commitments is generally dependent on the level of overall economic conditions within the Bank’s lending areas. Commercial, construction, and land borrowers’ ability to repay is generally dependent upon the health of the economy and real estate values, including, in particular, the performance of the construction sector. Accordingly, the ultimate collectability of a substantial portion of the Bank’s loan portfolio is susceptible to changing conditions in the New England, the San Francisco Bay Area, and Southern California economies and real estate markets. The following table presents a summary of the loan portfolio based on the portfolio segment as of the dates indicated: December 31, 2017 December 31, 2016 (In thousands) Commercial and industrial $ 520,992 $ 611,370 Commercial tax-exempt 418,698 398,604 Total commercial and industrial 939,690 1,009,974 Commercial real estate 2,440,220 2,302,244 Construction and land 164,990 104,839 Residential 2,682,533 2,379,861 Home equity 99,958 118,817 Consumer and other 177,637 198,619 Total $ 6,505,028 $ 6,114,354 The following table presents nonaccrual loans receivable by class of receivable as of the dates indicated: December 31, 2017 December 31, 2016 (In thousands) Commercial and industrial $ 748 $ 572 Commercial tax-exempt — — Total commercial and industrial 748 572 Commercial real estate 1,985 4,583 Construction and land 110 179 Residential 8,470 10,908 Home equity 2,840 1,072 Consumer and other 142 1 Total $ 14,295 $ 17,315 The Bank’s policy is to discontinue the accrual of interest on a loan when the collectability of principal or interest is in doubt. In certain instances, although infrequent, loans that have become 90 days or more past due may remain on accrual status if the value of the collateral securing the loan is sufficient to cover principal and interest and the loan is in the process of collection. There were no loans 90 days or more past due, but still accruing, as of December 31, 2017 and 2016 . The Bank’s policy for returning a loan to accrual status requires the loan to be brought current and for the client to show a history of making timely payments (generally six consecutive months). For TDRs, a return to accrual status generally requires timely payments for a period of six months in accordance with the restructured loan terms, along with meeting other criteria. The following tables present the payment status of loans receivable by class of receivable as of the dates indicated: December 31, 2017 Accruing Past Due Nonaccrual Loans 30-59 Days Past Due 60-89 Days Past Due Total Accruing Past Due Current 30-89 Days Past Due 90 Days or Greater Past Due Total Non- accrual Loans Current Accruing Loans Total Loans Receivable (In thousands) Commercial and industrial $ 10,903 $ 849 $ 11,752 $ 355 $ — $ 393 $ 748 $ 508,492 $ 520,992 Commercial tax-exempt — — — — — — — 418,698 418,698 Commercial real estate 4,043 — 4,043 163 — 1,822 1,985 2,434,192 2,440,220 Construction and land — — — — — 110 110 164,880 164,990 Residential 7,239 1,635 8,874 805 3,172 4,493 8,470 2,665,189 2,682,533 Home equity 355 — 355 — 71 2,769 2,840 96,763 99,958 Consumer and other 24 — 24 17 125 — 142 177,471 177,637 Total $ 22,564 $ 2,484 $ 25,048 $ 1,340 $ 3,368 $ 9,587 $ 14,295 $ 6,465,685 $ 6,505,028 December 31, 2016 Accruing Past Due Nonaccrual Loans 30-59 60-89 Total Current 30-89 90 Days Total Current Total (In thousands) Commercial and industrial $ 541 $ 1,078 $ 1,619 $ 537 $ — $ 35 $ 572 $ 609,179 $ 611,370 Commercial tax-exempt — — — — — — — 398,604 398,604 Commercial real estate 3,096 — 3,096 2,311 835 1,437 4,583 2,294,565 2,302,244 Construction and land — — — 129 12 38 179 104,660 104,839 Residential 3,646 536 4,182 2,148 1,274 7,486 10,908 2,364,771 2,379,861 Home equity 245 — 245 — 80 992 1,072 117,500 118,817 Consumer and other 5,995 — 5,995 1 — — 1 192,623 198,619 Total $ 13,523 $ 1,614 $ 15,137 $ 5,126 $ 2,201 $ 9,988 $ 17,315 $ 6,081,902 $ 6,114,354 Nonaccrual and delinquent loans are affected by many factors, such as economic and business conditions, interest rates, unemployment levels, and real estate collateral values, among others. In periods of prolonged economic decline, borrowers may become more severely affected over time as liquidity levels decline and the borrower’s ability to continue to make payments deteriorates. With respect to real estate collateral values, the declines from the peak, as well as the value of the real estate at the time of origination versus the current value, can impact the level of problem loans. For instance, if the loan to value ratio at the time of renewal has increased due to the decline in the real estate value since origination, the loan may no longer meet the Bank’s underwriting standards and may be considered for classification as a problem loan dependent upon a review of risk factors. Generally when a collateral dependent loan becomes impaired, an updated appraisal of the collateral, if appropriate, is obtained. If the impaired loan has not been upgraded to a performing status within a reasonable amount of time, the Bank will continue to obtain updated appraisals as deemed necessary, especially during periods of declining property values. The past due status of a loan is determined in accordance with its contractual repayment terms. All loan types are reported past due when one scheduled payment is due and unpaid for 30 days or more. The following tables present the loan portfolio’s credit risk profile by internally assigned grade and class of receivable as of the dates indicated: December 31, 2017 By Loan Grade or Nonaccrual Status Pass Special Accruing Nonaccrual Total (In thousands) Commercial and industrial $ 496,395 $ 12,898 $ 10,951 $ 748 $ 520,992 Commercial tax-exempt 413,139 5,559 — — 418,698 Commercial real estate 2,346,833 56,947 34,455 1,985 2,440,220 Construction and land 146,514 11,770 6,596 110 164,990 Residential 2,672,714 — 1,349 8,470 2,682,533 Home equity 97,118 — — 2,840 99,958 Consumer and other 177,494 — 1 142 177,637 Total $ 6,350,207 $ 87,174 $ 53,352 $ 14,295 $ 6,505,028 December 31, 2016 By Loan Grade or Nonaccrual Status Pass Special Mention Accruing Substandard Nonaccrual Loans Total (In thousands) Commercial and industrial $ 591,388 $ 10,133 $ 9,277 $ 572 $ 611,370 Commercial tax-exempt 388,544 10,060 — — 398,604 Commercial real estate 2,230,732 17,233 49,696 4,583 2,302,244 Construction and land 101,254 109 3,297 179 104,839 Residential 2,367,554 — 1,399 10,908 2,379,861 Home equity 117,745 — — 1,072 118,817 Consumer and other 198,616 — 2 1 198,619 Total $ 5,995,833 $ 37,535 $ 63,671 $ 17,315 $ 6,114,354 The following tables present, by class of receivable, the balance of impaired loans with and without a related allowance, the associated allowance for those impaired loans with a related allowance, and the total unpaid principal on impaired loans: As of and for the year ended December 31, 2017 Recorded Investment (1) Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized while Impaired (In thousands) With no related allowance recorded: Commercial and industrial $ 1,434 $ 2,238 n/a $ 1,594 $ 50 Commercial tax-exempt — — n/a 1,001 80 Commercial real estate 1,832 3,453 n/a 3,098 1,546 Construction and land 109 109 n/a 172 — Residential 9,337 9,709 n/a 9,033 360 Home equity 1,779 1,779 n/a 413 — Consumer and other — — n/a — — Subtotal $ 14,491 $ 17,288 n/a $ 15,311 $ 2,036 With an allowance recorded: Commercial and industrial $ 242 $ 242 $ 58 $ 156 $ 4 Commercial tax-exempt — — — — — Commercial real estate 6,855 7,284 362 6,980 322 Construction and land — — — — — Residential 828 828 89 2,469 89 Home equity 36 36 20 36 1 Consumer and other 125 250 125 10 — Subtotal $ 8,086 $ 8,640 $ 654 $ 9,651 $ 416 Total: Commercial and industrial $ 1,676 $ 2,480 $ 58 $ 1,750 $ 54 Commercial tax-exempt — — — 1,001 80 Commercial real estate 8,687 10,737 362 10,078 1,868 Construction and land 109 109 — 172 — Residential 10,165 10,537 89 11,502 449 Home equity 1,815 1,815 20 449 1 Consumer and other 125 250 125 10 — Total $ 22,577 $ 25,928 $ 654 $ 24,962 $ 2,452 ___________________ (1) Recorded investment represents the client loan balance net of historical charge-offs and historical nonaccrual interest paid, which was applied to principal. As of and for the year ended December 31, 2016 Recorded Investment (1) Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized while Impaired (In thousands) With no related allowance recorded: Commercial and industrial $ 1,793 $ 2,155 n/a $ 5,288 $ 249 Commercial tax-exempt — — n/a — — Commercial real estate 4,488 9,647 n/a 8,520 1,032 Construction and land 179 507 n/a 1,069 48 Residential 8,134 8,506 n/a 7,446 211 Home equity — — n/a — — Consumer and other — — n/a — — Subtotal $ 14,594 $ 20,815 n/a $ 22,323 $ 1,540 With an allowance recorded: Commercial and industrial $ — $ — $ — $ 31 $ 1 Commercial tax-exempt — — — — — Commercial real estate 7,115 7,544 548 7,230 314 Construction and land — — — 507 — Residential 4,284 4,284 565 5,505 143 Home equity 37 37 22 3 — Consumer and other — — — — — Subtotal $ 11,436 $ 11,865 $ 1,135 $ 13,276 $ 458 Total: Commercial and industrial $ 1,793 $ 2,155 $ — $ 5,319 $ 250 Commercial tax-exempt — — — — — Commercial real estate 11,603 17,191 548 15,750 1,346 Construction and land 179 507 — 1,576 48 Residential 12,418 12,790 565 12,951 354 Home equity 37 37 22 3 — Consumer and other — — — — — Total $ 26,030 $ 32,680 $ 1,135 $ 35,599 $ 1,998 ____________________ (1) Recorded investment represents the client loan balance net of historical charge-offs and historical nonaccrual interest paid, which was applied to principal. When management determines that it is probable that the Bank will not collect all principal and interest on a loan in accordance with the original loan terms, the loan is designated as impaired. Loans that are designated as impaired require an analysis to determine the amount of impairment, if any. Impairment would be indicated as a result of the carrying value of the loan exceeding the estimated collateral value, less costs to sell, for collateral dependent loans or the net present value of the projected cash flow, discounted at the loan’s contractual effective interest rate, for loans not considered to be collateral dependent. Generally, shortfalls in the analysis on collateral dependent loans would result in the impairment amount being charged-off to the allowance for loan losses. Shortfalls on cash flow dependent loans may be carried as specific allocations to the general reserve unless a known loss is determined to have occurred, in which case such known loss is charged-off. Loans in the held for sale category are carried at the lower of amortized cost or estimated fair value in the aggregate and are excluded from the allowance for loan losses analysis. The Bank may, under certain circumstances, restructure loans as a concession to borrowers who are experiencing financial difficulty. Such loans are classified as TDRs and are included in impaired loans. TDRs typically result from the Bank’s loss mitigation activities which, among other things, could include rate reductions, payment extensions, and/or principal forgiveness. As of December 31, 2017 and 2016 , TDRs totaled $13.6 million and $18.1 million , respectively. As of December 31, 2017 , $11.1 million of the $13.6 million of TDRs were on accrual status. As of December 31, 2016 , $12.4 million of the $18.1 million of TDRs were on accrual status. As of December 31, 2017 and 2016 , the Company had no commitments to lend additional funds to debtors for loans whose terms had been modified in a troubled debt restructuring. Since all TDR loans are considered impaired loans, they are individually evaluated for impairment. The resulting impairment, if any, would have an impact on the allowance for loan losses as a specific reserve or charge-off. If, prior to the classification as a TDR, the loan was not impaired, there would have been a general or allocated reserve on the particular loan. Therefore, depending upon the result of the impairment analysis, there could be an increase or decrease in the related allowance for loan losses. Many loans initially categorized as TDRs are already on nonaccrual status and are already considered impaired. Therefore, there is generally not a material change to the allowance for loan losses when a nonaccruing loan is categorized as a TDR. The following tables present the balance of TDRs that were restructured or defaulted during the periods indicated: As of and for the year ended December 31, 2017 Restructured Year to Date TDRs that defaulted that were restructured in prior twelve months # of Loans Pre- modification recorded investment Post- # of Loans Post- modification recorded investment (In thousands, except number of loans) Commercial and industrial — $ — $ — — $ — Commercial tax-exempt — — — — — Commercial real estate — — — — — Construction and land — — — — — Residential (1) 1 108 109 — — Home equity — — — — — Consumer and other — — — — — Total 1 $ 108 $ 109 — $ — ____________________ (1) Represents the following concession: temporary rate reduction. As of and for the year ended December 31, 2016 Restructured Year to Date TDRs that defaulted that were restructured in prior twelve months # of Loans Pre- modification recorded investment Post- # of Loans Post- modification recorded investment (In thousands, except number of loans) Commercial and industrial 3 $ 7,384 $ 7,209 — $ — Commercial tax-exempt — — — — — Commercial real estate 1 1,276 1,276 1 1,276 Construction and land — — — — — Residential 5 1,709 1,721 — — Home equity — — — — — Consumer and other — — — — — Total 9 $ 10,369 $ 10,206 1 $ 1,276 As of and for the year ended December 31, 2016 Extension of Term Temporary Rate Reduction Payment Deferral Combination of Concessions (1) Total Concessions # of Loans Post- # of Loans Post- # of Loans Post- # of Loans Post- # of Loans Post- (In thousands, except number of loans) Commercial and Industrial 2 $ 7,209 — $ — — $ — 1 $ — 3 $ 7,209 Commercial tax-exempt — — — — — — — — — — Commercial real estate — — — — — — 1 1,276 1 1,276 Construction and Land — — — — — — — — — — Residential — — 4 519 1 1,202 — — 5 1,721 Home Equity — — — — — — — — — — Consumer and other — — — — — — — — — — ____________________ (1) Combination of concessions includes loans that have had more than one modification, including extension of term, temporary reduction of interest rate, and/or payment deferral. Any loans to senior management, executive officers, and directors are made in the ordinary course of business, under normal credit terms, including interest rates and collateral requirements prevailing at the time of origination for comparable transactions with other persons and do not represent more than normal credit risk. The Bank’s current policy is generally not to originate these types of loans. Total loans include deferred loan origination (fees)/ costs, net, of $6.9 million and $5.9 million as of December 31, 2017 and 2016 , respectively. Mortgage loans serviced for others totaled $41.4 million and $58.6 million as of December 31, 2017 and 2016 , respectively, and are not included in the Company’s total loans.

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Allowance for Loan Losses [Abstract]
Allowance for Credit Losses [Text Block]	ALLOWANCE FOR LOAN LOSSES The allowance for loan losses is reported as a reduction of outstanding loan balances, and totaled $74.7 million and $78.1 million at December 31, 2017 and 2016 , respectively. The following table presents a summary of the changes in the allowance for loan losses for the periods indicated: As of and for the year ended December 31, 2017 2016 2015 (In thousands) Allowance for loan losses, beginning of year: Commercial and industrial $ 12,751 $ 15,814 $ 14,114 Commercial real estate 50,412 44,215 43,854 Construction and land 3,039 6,322 4,041 Residential 10,449 10,544 10,374 Home equity 1,035 1,085 1,003 Consumer and other 391 520 382 Unallocated (1) — — 2,070 Total allowance for loan losses, beginning of year 78,077 78,500 75,838 Loans charged-off: Commercial and industrial (393 ) (2,851 ) (253 ) Commercial real estate — — (1,400 ) Construction and land — (400 ) — Residential (58 ) (605 ) (313 ) Home equity — — — Consumer and other (412 ) (93 ) (70 ) Total charge-offs (863 ) (3,949 ) (2,036 ) Recoveries on loans previously charged-off: Commercial and industrial 472 3,212 2,471 Commercial real estate 4,621 6,040 2,482 Construction and land 25 1,117 1,158 Residential 47 65 141 Home equity — — — Consumer and other 32 27 1 Total recoveries 5,197 10,461 6,253 Provision/ (credit) for loan losses: Commercial and industrial (1,095 ) (3,424 ) (518 ) Commercial real estate (8,213 ) 157 (721 ) Construction and land 1,885 (4,000 ) 1,123 Residential (665 ) 445 342 Home equity (200 ) (50 ) 82 Consumer and other 619 (63 ) 207 Unallocated (1) — — (2,070 ) Total provision/(credit) for loan losses (7,669 ) (6,935 ) (1,555 ) As of and for the year ended December 31, 2017 2016 2015 (In thousands) Allowance for loan losses at December 31 (end of year): Commercial and industrial 11,735 12,751 15,814 Commercial real estate 46,820 50,412 44,215 Construction and land 4,949 3,039 6,322 Residential 9,773 10,449 10,544 Home equity 835 1,035 1,085 Consumer and other 630 391 520 Total allowance for loan losses at December 31 (end of year) $ 74,742 $ 78,077 $ 78,500 __________________ (1) As of December 31, 2015, the unallocated reserve was allocated to the qualitative factors as part of the general reserve (ASC 450). The allocation had no effect on the 2015 provision/ (credit) for loan losses. The provision/ (credit) for loan losses and related balance in the allowance for loan losses for tax-exempt commercial and industrial loans are included with commercial and industrial. The provision/ (credit) for loan losses and related balance in the allowance for loan losses for tax-exempt commercial real estate loans are included with commercial real estate. There were no charge-offs or recoveries, for any period presented, for both commercial and industrial and commercial real estate tax-exempt loans. The following tables present the Company’s allowance for loan losses and loan portfolio at December 31, 2017 and 2016 by portfolio segment, disaggregated by method of analysis. The Company had no loans acquired with deteriorated credit quality at December 31, 2017 or 2016 . December 31, 2017 Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Recorded investment (loan balance) Allowance for loan losses Recorded Allowance Recorded Allowance (In thousands) Commercial and industrial $ 1,676 $ 58 $ 938,014 $ 11,677 $ 939,690 $ 11,735 Commercial real estate 8,687 362 2,431,533 46,458 2,440,220 46,820 Construction and land 109 — 164,881 4,949 164,990 4,949 Residential 10,165 89 2,672,368 9,684 2,682,533 9,773 Home equity 1,815 20 98,143 815 99,958 835 Consumer 125 125 177,512 505 177,637 630 Total $ 22,577 $ 654 $ 6,482,451 $ 74,088 $ 6,505,028 $ 74,742 December 31, 2016 Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Recorded Allowance Recorded Allowance Recorded Allowance (In thousands) Commercial and industrial $ 1,793 $ — $ 1,008,181 $ 12,751 $ 1,009,974 $ 12,751 Commercial real estate 11,603 548 2,290,641 49,864 2,302,244 50,412 Construction and land 179 — 104,660 3,039 104,839 3,039 Residential 12,418 565 2,367,443 9,884 2,379,861 10,449 Home equity 37 22 118,780 1,013 118,817 1,035 Consumer — — 198,619 391 198,619 391 Total $ 26,030 $ 1,135 $ 6,088,324 $ 76,942 $ 6,114,354 $ 78,077

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
PREMISES AND EQUIPMENT [Abstract]
Property, Plant and Equipment Disclosure [Text Block]	PREMISES AND EQUIPMENT Premises and equipment consisted of the following: As of December 31, 2017 2016 (In thousands) Leasehold improvements $ 51,161 $ 46,031 Furniture, fixtures, and equipment 39,618 53,156 Buildings 3,159 3,159 Subtotal 93,938 102,346 Less: accumulated depreciation and amortization 56,298 70,519 Premises and equipment, net $ 37,640 $ 31,827 Depreciation and amortization expense related to premises and equipment was $8.1 million , $6.8 million , and $6.6 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The Company is obligated for minimum payments under non-cancelable operating leases. In accordance with the terms of these leases, the Company is currently committed to minimum annual payments as follows: Minimum lease payments (In thousands) 2018 $ 21,066 2019 20,504 2020 19,718 2021 19,460 2022 19,221 Thereafter 58,076 Total $ 158,045 Rent expense for the years ended December 31, 2017 , 2016 , and 2015 was $21.4 million , $19.6 million and $19.0 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
GOODWILL AND OTHER INTANGIBLE ASSETS [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill The following tables detail the changes in carrying value of goodwill by segment during the years ended December 31, 2017 and 2016 . There were no changes in the carrying value of goodwill during 2015. As of December 31, 2015 Impairment As of December 31, 2016 (In thousands) Goodwill Private Banking $ — $ — $ — Wealth Management and Trust 44,305 (9,528 ) 34,777 Investment Management 66,955 — 66,955 Wealth Advisory 40,822 — 40,822 Total goodwill $ 152,082 $ (9,528 ) $ 142,554 As of December 31, 2016 Impairment Adjustments or Reclasses As of December 31, 2017 (In thousands) Goodwill Private Banking $ — $ — $ — $ — Wealth Management and Trust 34,777 — — 34,777 Investment Management (1) 66,955 (24,901 ) (42,054 ) — Wealth Advisory (2) 40,822 — (1 ) 40,821 Total goodwill $ 142,554 $ (24,901 ) $ (42,055 ) $ 75,598 ___________________ (1) Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017. (2) Adjusted for rounding. The following tables detail total goodwill and the cumulative impairment charges thereon as of December 31, 2017 and 2016 : Goodwill prior to impairment Cumulative goodwill impairment Goodwill (In thousands) Private Banking $ 34,281 $ (34,281 ) $ — Wealth Management and Trust 44,305 (9,528 ) 34,777 Investment Management (1) 75,162 (75,162 ) — Wealth Advisory (2) 40,821 — 40,821 Total goodwill at December 31, 2017 $ 194,569 $ (118,971 ) $ 75,598 Private Banking $ 34,281 $ (34,281 ) $ — Wealth Management and Trust 44,305 (9,528 ) 34,777 Investment Management 117,216 (50,261 ) 66,955 Wealth Advisory 40,822 — 40,822 Total goodwill at December 31, 2016 $ 236,624 $ (94,070 ) $ 142,554 ___________________ (1) Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017. (2) Adjusted for rounding. In 2017 and 2016, the Company recognized no additional goodwill. Goodwill and indefinite lived intangible assets such as trade names are subject to annual impairment tests, or more frequently, if there is an indication of impairment, based on the guidance in ASC 350, Intangibles-Goodwill and Other (“ASC 350”). Long-lived intangible assets such as advisory contracts are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount of the asset or asset group may not be recoverable in accordance with ASC 360, Property, Plant, and Equipment (“ASC 360”). Management performed its annual goodwill and indefinite-lived intangible asset impairment testing during the fourth quarter of 2017 for applicable reporting units. There was no additional testing required for long-lived intangible assets in 2017. 2017 Impairment testing and results Management performed its annual goodwill and indefinite-lived intangible asset impairment testing during the fourth quarters of 2017 for applicable reporting units. For the 2017 testing, Step 0 was performed for BOS and KLS. A Step 1 test was performed for Boston Private Wealth and Anchor. The results of the Step 1 test for Boston Private Wealth indicated that the fair value exceeded their carrying value therefore no goodwill impairment was evident. Neither Boston Private Bank nor DGHM have any goodwill. In December 2017, while the Company was performing the Step 1 test for Anchor, the Company entered into an agreement to sell its entire ownership interest in Anchor in a transaction that will result in Anchor being majority owned by members of its management team. The Company will receive approximately $32 million of cash at closing and future revenue share payments that, at signing, had a net present value of approximately $15 million , subject to purchase price adjustments. The Company’s annual goodwill impairment test for Anchor resulted in a fourth quarter of 2017 goodwill impairment charge of $24.9 million . The decline in fair value and the related goodwill impairment was related to the fair market value impacts of the Anchor sale transaction. Due to the limited interest and terms of the transaction that were required for a mutual agreement, the fair value obtained was substantially below the carrying value. The fair value was based on the terms of the sale transaction. The transaction is expected to close in the first quarter of 2018. This transaction has been approved by the Company’s board of directors and is subject to obtaining client consents, Anchor raising debt financing, and customary closing conditions. The rationale for the sale is to focus the Company’s resources in businesses where we can offer holistic financial advice, along with integrated wealth management, trust, and private banking capabilities. This transaction will also generate additional capital for us to reinvest in a more focused Company. 2016 Impairment testing and results In the 2016 goodwill impairment testing, a Step 0 test was performed for BOS and KLS and a Step 1 test was performed for Anchor and Boston Private Wealth. Neither Boston Private Bank nor DGHM have any goodwill. Based on the qualitative factors assessed in the Step 0 tests for BOS and KLS, no additional testing was required. Anchor passed its Step 1 test although with a lower fair value than the previous year. Boston Private Wealth failed its Step 1 test and the Company performed a Step 2 test to determine the amount of goodwill impairment, if any. The estimated fair value of Boston Private Wealth was $68.0 million as compared to a carrying value of $76.9 million, resulting in a deficit of $8.9 million, or 11.6%. Because the estimated fair value of Boston Private Wealth was lower than its carrying value, the Company was required to perform a Step 2 valuation. The results of the Step 2 valuation indicated an implied fair value of goodwill of $34.8 million as compared to the book value of $44.3 million, or a deficiency of $9.5 million. The resulting deficiency was recorded as a goodwill impairment charge within operating expenses in the fourth quarter of 2016. As a result of the goodwill impairment, the carrying value of goodwill at Boston Private Wealth was reduced to $34.8 million. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 1: “Basis of Presentation and Summary of Significant Accounting Policies” for changes to the rules in goodwill impairment testing as discussed in the Recent Accounting Pronouncements section. Intangible assets The following table shows the gross and net carrying amounts of identifiable intangible assets at December 31, 2017 and 2016 : 2017 2016 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net (In thousands) Advisory contracts (1) $ 37,313 $ 21,370 $ 15,943 $ 71,513 $ 46,828 $ 24,685 Trade names (1) 140 — 140 2,040 — 2,040 Total $ 37,453 $ 21,370 $ 16,083 $ 73,553 $ 46,828 $ 26,725 ___________________ (1) Intangible assets of Anchor are classified as held for sale as of December 31, 2017. The Company recognized no additional identifiable intangible assets in 2017 or 2016. Consolidated expense related to intangible assets subject to amortization was $5.6 million , $6.3 million , and $6.7 million for 2017 , 2016 , and 2015 , respectively. Management reviews, and adjusts if necessary, intangible asset amortization schedules to ensure that the remaining life on the amortization schedule accurately reflects the useful life of the intangible asset. The weighted average amortization period of these intangible assets is 6.68 years . The estimated annual amortization expense for these identifiable intangibles over the next five years is: Estimated intangible amortization expense (In thousands) 2018 $ 2,970 2019 2,848 2020 2,588 2021 2,110 2022 2,056

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	DERIVATIVES AND HEDGING ACTIVITIES The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and, to a lesser extent, the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are generally determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to certain loans, deposits, and borrowings. The following table presents the fair value of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets as of December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Asset derivatives Liability derivatives Asset derivatives Liability derivatives Balance sheet location Fair value (1) Balance sheet location Fair Balance sheet location Fair Balance sheet location Fair (In thousands) Derivatives designated as hedging instruments: Interest rate products Other assets $ 555 Other liabilities $ (80 ) Other assets $ — Other liabilities $ (1,040 ) Derivatives not designated as hedging instruments: Interest rate products Other assets 18,575 Other liabilities (18,953 ) Other assets 17,032 Other liabilities (16,560 ) Foreign exchange contracts Other assets 2 Other liabilities (2 ) Other assets — Other liabilities — Risk participation agreements Other assets 1 Other liabilities (108 ) Other assets 15 Other liabilities (6 ) Total $ 19,133 $ (19,143 ) $ 17,047 $ (17,606 ) ___________________ (1) For additional details, see Part II. Item 8. “Financial Statements and Supplementary Data - Note 21: Fair Value of Financial Instruments.” The following table presents the effect of the Company’s derivative financial instruments in the consolidated statement of operations for the years ended December 31, 2017 and 2016 . Derivatives in Cash Flow Hedging Relationships Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) (1) Years Ended December 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)Years Ended December 31, 2017 2016 2017 2016 (In thousands) Interest rate products $ 336 $ (799 ) Interest Expense $ (1,168 ) $ (1,672 ) Total $ 336 $ (799 ) $ (1,168 ) $ (1,672 ) ___________________ (1) There was an additional $(11) thousand loss related to the ineffective portion for the year ended December 31, 2017 and an additional $6 thousand gain related to the ineffective portion for the year ended December 31, 2016. The Bank has agreements with its derivative counterparties that contain provisions where, if the Bank defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Bank could also be declared in default on its derivative obligations. The Bank was in compliance with these provisions as of December 31, 2017 and 2016 . The Bank also has agreements with certain of its derivative counterparties that contain provisions where, if the Bank fails to maintain its status as a well- or adequately-capitalized institution, then the counterparty could terminate the derivative positions and the Bank would be required to settle its obligations under the agreements. The Bank was in compliance with these provisions as of December 31, 2017 and 2016 . Certain of the Bank’s agreements with its derivative counterparties contain provisions where if specified events or conditions occur that materially change the Bank’s creditworthiness in an adverse manner, the Bank may be required to fully collateralize their obligations under the derivative instruments. The Bank was in compliance with these provisions as of December 31, 2017 and 2016 . As of December 31, 2017 and 2016 , the termination amounts related to collateral determinations of derivatives in a liability position was $3.1 million and $3.4 million , respectively. The Company has minimum collateral posting thresholds with its derivative counterparties and has pledged securities with market values of $2.3 million and $1.9 million , respectively, as of December 31, 2017 and 2016 , against its obligations under these agreements. The collateral posted is typically greater than the current liability position; however, due to timing of liability position changes at period end, the funding of a collateral shortfall may take place shortly following period end. Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements. To accomplish these objectives, the Company has entered into interest rate swaps as part of its interest rate risk management strategy. These interest rate swaps are designated as cash flow hedges and involve the receipt of variable rate amounts from a counterparty in exchange for the Company making fixed payments. The Company has entered into interest rate swaps to hedge London Interbank Offered Rate (“LIBOR”) -indexed brokered deposits and the LIBOR component of the total cost of certain FHLB borrowings. The Bank has entered into a total of six interest rate swaps, two during 2017 with effective dates of March 22, 2017 and four during 2013 with effective dates of September 2, 2014, June 1, 2014, March 1, 2014, and August 1, 2013. The two interest rate swaps entered into during 2017 have notional amounts of $40 million and $60 million with terms of 1.75 and 2.25 years, respectively, from their effective dates. These interest rate swaps will effectively fix the Bank’s interest payments on $100 million in interest-related cash outflows attributable to changes in the LIBOR component of FHLB borrowing liabilities at rates of 1.55% and 1.65%, respectively, with a weighted average rate of 1.61%. The borrowings hedged will initially be expected to be issuances and quarterly rollovers of 3-month FHLB advances but may also then include future issuances of 3-month repurchase agreements with similar characteristics and/or future issuances of either floating or fixed rate borrowings that are issued with the specific intent to replace the quarterly rollovers of the advances or repurchase agreements. The four interest rate swaps entered into during 2013 each have a notional amount of $25 million and have terms ranging from four to six years from their respective effective dates. The interest rate swaps effectively fix the Bank’s interest payments on $100 million of its LIBOR-indexed liabilities at rates between 1.68% and 2.32%, and a weighted average rate of 1.95%. The Company uses the “Hypothetical Derivative Method” described in ASC 815, Derivatives and Hedging (“ASC 815”), for quarterly prospective and retrospective assessments of hedge effectiveness, as well as for measurements of hedge ineffectiveness. Under this method, the Company assesses the effectiveness of each hedging relationship by comparing the changes in cash flows of the derivative hedging instrument with the changes in cash flows of the designated hedged transactions. The effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (“OCI”) (outside of earnings) and subsequently reclassified to earnings in interest and dividend income when the hedged transactions affect earnings. Ineffectiveness resulting from the hedge is recorded as a gain or loss in the consolidated statement of operations as part of fees and other income. There was an immaterial amount of hedge ineffectiveness during the years ended December 31, 2017 and December 31, 2016 . The Company also monitors the risk of counterparty default on an ongoing basis. A portion of the balance reported in accumulated other comprehensive income related to derivatives will be reclassified to interest expense as interest payments are made or received on the Company’s interest rate swaps. During the next twelve months, the Company estimates that $0.2 million will be reclassified as a decrease to interest expense. Non-designated Hedges Derivatives not designated as hedges are not speculative and result from two different services the Bank provides to qualified commercial clients. The Bank offers certain derivative products directly to such clients. The Bank economically hedges derivative transactions executed with commercial clients by entering into mirror-image, offsetting derivatives with third parties. Derivative transactions executed as part of these programs are not designated in ASC 815-qualifying hedging relationships and are, therefore, marked-to-market through earnings each period. Because the derivatives have mirror-image contractual terms, the changes in fair value substantially offset through earnings. The net effect on earnings is primarily driven by changes in the credit valuation adjustment (“CVA”). The CVA represents the dollar amount of fair value adjustment related to nonperformance risk of both the Bank and its counterparties. Fees earned in connection with the execution of derivatives related to this program are recognized in the consolidated statement of operations in other income. As of December 31, 2017 and 2016 , the Bank had 142 and 136 derivatives, respectively, related to this program, comprised of interest rate swaps and caps, with an aggregate notional amount of $1.1 billion for each period. As of December 31, 2017 , there were three foreign currency exchange contracts with an aggregate notional amount of $0.2 million and, as of December 31, 2016, there was one foreign currency exchange contract with an aggregate notional amount of less than $0.1 million . In addition, as a participant lender, the Bank has guaranteed performance on the pro-rated portion of swaps executed by other financial institutions. As the participant lender, the Bank is providing a partial guarantee, but is not a direct party to the related swap transactions. The Bank has no obligations under the risk participation agreements unless the borrower defaults on their swap transaction with the lead bank and the swap is in a liability position to the borrower. In that instance, the Bank has agreed to pay the lead bank a portion of the swap’s termination value at the time of the default. The derivative transactions entered into as part of these transactions are not designated, as per ASC 815, as qualifying hedging relationships and are, therefore, marked-to-market through earnings each period. As of December 31, 2017 there were six of these risk participation agreements with an aggregate notional amount of $48.0 million and, as of December 31, 2016, there were two of these risk participation agreements with an aggregate notional amount of $13.3 million . The Bank has also participated out to another financial institution a pro-rated portion of two swaps executed by the Bank. The other financial institution has no obligations under the risk participation agreements unless the borrowers default on their swap transactions with the Bank and the swaps are in liability positions to the borrower. In those instances, the other financial institution has agreed to pay the Bank a portion of the swap’s termination value at the time of the default. The derivative transactions entered into as part of these agreements are not designated, as per ASC 815, as qualifying hedging relationships and are, therefore, marked-to-market through earnings each period. The pro-rated notional amount of these risk participation agreements was $6.1 million as of both December 31, 2017 and December 31, 2016. The following table presents the effect of the Bank’s derivative financial instruments, not designated as hedging instruments, in the consolidated statements of operations for the years ended December 31, 2017 and 2016 . Derivatives Not Designated as Hedging Instruments Location of Gain or (Loss) Recognized in Income on Derivatives Amount of Gain or (Loss), Net, Recognized in Income on Derivatives for Years Ended December 31, 2017 2016 (In thousands) Interest rate products Other income/(expense) $ (851 ) $ 596 Risk participation agreements Other income/(expense) 354 4 Total $ (497 ) $ 600

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposit Liabilities Disclosures [Text Block]	DEPOSITS Deposits are summarized as follows: December 31, 2017 2016 (In thousands) Demand deposits (non-interest bearing) $ 2,025,690 $ 1,753,648 Savings and NOW (1) 716,296 652,819 Money market (1) 3,121,811 3,102,048 Certificates of deposit under $100,000 (1) 250,070 236,001 Certificates of deposit $100,000 or more to less than $250,000 (1) 82,665 100,570 Certificates of deposit $250,000 or more 313,714 240,060 Total $ 6,510,246 $ 6,085,146 ___________________ (1) Includes brokered deposits. Certificates of deposit had the following schedule of maturities: December 31, 2017 2016 (In thousands) Less than 3 months remaining $ 214,594 $ 140,304 3 to 6 months remaining 183,780 73,522 6 to 12 months remaining 133,873 213,802 Total due within 1 year 532,247 427,628 1 to 2 years remaining 79,926 115,099 2 to 3 years remaining 32,165 14,492 3 to 4 years remaining 2,083 17,437 4 to 5 years remaining 25 1,972 More than 5 years remaining 3 3 Total $ 646,449 $ 576,631 Interest expense on certificates of deposit $100,000 or greater was $3.1 million , $2.0 million and $2.3 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. At December 31, 2017 and 2016 , there was $0.4 million and $0.2 million of overdrawn deposit accounts reclassified to loans, respectively.

Federal Funds Purchased and Sec

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase	12 Months Ended
	Dec. 31, 2017
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Short-term Debt [Text Block]	FEDERAL FUNDS PURCHASED AND SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE Federal Funds Purchased Securities Sold Under Agreements to Repurchase (In thousands) 2017 Outstanding at end of year $ 30,000 $ 32,169 Maximum outstanding at any month-end 100,000 67,249 Average balance for the year 22,742 58,872 Weighted average rate at end of year 1.50 % 0.09 % Weighted average rate paid for the year 1.19 % 0.09 % 2016 Outstanding at end of year $ 80,000 $ 59,624 Maximum outstanding at any month-end 180,000 77,466 Average balance for the year 29,542 66,282 Weighted average rate at end of year 0.75 % 0.05 % Weighted average rate paid for the year 0.54 % 0.05 % 2015 Outstanding at end of year $ — $ 58,215 Maximum outstanding at any month-end 102,000 75,313 Average balance for the year 10,008 64,320 Weighted average rate at end of year — % 0.05 % Weighted average rate paid for the year 0.31 % 0.05 % The federal funds purchased generally mature within 30 days of the transaction date. Repurchase agreements are generally linked to commercial demand deposit accounts with an overnight sweep feature. In a repurchase agreement transaction, the Bank will generally sell an investment security, agreeing to repurchase either the same or a substantially identical security on a specified later date at a price slightly greater than the original sales price. The difference in the sale price and repurchase price is the cost of the use of the proceeds, or interest expense. Repurchase transactions are accounted for as financing arrangements rather than as sales of such securities, and the obligation to repurchase such securities is reflected as a liability in the Company’s consolidated balance sheets. The securities underlying the agreements remain under the Company’s control. Investment securities with a fair value of $144.3 million and $182.7 million were pledged as collateral for the securities sold under agreements to repurchase at December 31, 2017 and 2016 , respectively. As of December 31, 2017 and 2016 , the Bank had unused federal funds lines with correspondent banks of $435.0 million and $485.0 million , respectively.

Federal Home Loan Bank Borrowin

Federal Home Loan Bank Borrowings	12 Months Ended
	Dec. 31, 2017
FEDERAL HOME LOAN BANK BORROWINGS [Abstract]
Federal Home Loan Bank Advances, Disclosure [Text Block]	FEDERAL HOME LOAN BANK BORROWINGS The Bank is a member of the Federal Home Loan Bank (“FHLB”) of Boston. As a member of the FHLB of Boston, the Bank has access to short- and long-term borrowings. Borrowings from the FHLB are secured by the Bank’s stock investment in the FHLB and a blanket lien on “qualified collateral” defined principally as a percentage of the principal balance of certain types of mortgage loans. The stock investment cannot be used for additional borrowing collateral. The percentage of collateral valuation from the FHLB varies between 50% and 82% based on the underlying collateral. The Bank had loans pledged as collateral with a book value of $2.5 billion and $2.3 billion at December 31, 2017 and 2016 , respectively. The Bank had borrowings outstanding of $693.7 million and $734.2 million at December 31, 2017 and 2016 , respectively. Based on the collateral and the valuations applied, less the borrowings outstanding, the Bank had available credit with the FHLB of Boston of $1.2 billion and $0.9 billion at December 31, 2017 and 2016 , respectively. A summary of borrowings from the FHLBs is as follows: December 31, 2017 Amount Weighted Average Rate (In thousands) Within 1 year $ 529,720 1.55 % Over 1 to 2 years 59,018 1.45 % Over 2 to 3 years 54,365 2.89 % Over 3 to 4 years 37,045 2.01 % Over 4 to 5 years 3,985 1.93 % Over 5 years 9,548 2.57 % Total $ 693,681 1.69 % As of December 31, 2017 , the Company had no FHLB borrowings that were callable by the FHLB prior to maturity. As of December 31, 2016 , the Company had $5.0 million of FHLB borrowings that were callable by the FHLB prior to maturity. FHLB Stock As a member of the FHLB, the Bank is required to own FHLB stock based on a percentage of outstanding advances in addition to a membership stock ownership requirement. For the borrowings with the FHLB of Boston, the Bank is required to own FHLB stock of at least 3.0% to 4.0% of outstanding advances depending on the terms of the advance. In addition, the Bank is required to have a minimum membership stock investment which is based on a percentage of certain assets as reported in the Bank’s FDIC Call Report. FHLB of Boston stock owned in excess of the minimum requirements can be redeemed at par upon request by a member. As of December 31, 2017 and 2016 , the Bank’s FHLB stock holdings totaled $46.1 million and $44.1 million . respectively. The Bank’s investment in FHLB stock is recorded at cost and is redeemable at par.

Junior Subordinated Debentures

Junior Subordinated Debentures	12 Months Ended
	Dec. 31, 2017
JUNIOR SUBORDINATED DEBENTURES [Abstract]
Subordinated Borrowings Disclosure [Text Block]	JUNIOR SUBORDINATED DEBENTURES The schedule below presents the detail of the Company’s junior subordinated debentures: December 31, 2017 2016 (In thousands) Boston Private Capital Trust II Junior Subordinated Debentures $ 103,093 $ 103,093 Boston Private Capital Trust I Junior Subordinated Debentures 3,270 3,270 Total $ 106,363 $ 106,363 All of the Company’s junior subordinated debentures mature in more than five years. Boston Private Capital Trust II Junior Subordinated Debentures In September 2005, the Company and Boston Private Capital Trust II, a Delaware statutory trust (“Trust II”) entered into a Purchase Agreement for the sale of $100 million of trust preferred securities issued by Trust II and guaranteed by the Company on a subordinated basis. Trust II’s preferred securities pay interest quarterly and had an annual distribution rate of 6.25% up to, but not including, December 30, 2010. Subsequently, Trust II’s preferred securities converted to a floating rate of a three-month LIBOR plus 1.68% ; provided, however, that the interest rate does not exceed the highest rate permitted by New York law, and may be modified by the U.S. law of general application . At December 31, 2017 , the interest rate for the Trust II’s preferred securities was 3.02% . Each of the Trust II preferred securities represents an undivided beneficial interest in the assets of Trust II. The Company owns all of Trust II’s common securities. Trust II’s only assets are the junior subordinated debentures issued to it by the Company on substantially the same payment terms as Trust II’s preferred securities. The Company’s investment in Trust II was $3.1 million at both December 31, 2017 and 2016 . The junior subordinated debentures mature on December 30, 2035 and became redeemable after December 30, 2010 . The Company has the following covenants with regard to Trust II: • for so long as Trust II’s preferred securities remain outstanding, the Company shall maintain 100% ownership of the Trust II’s common securities; • the Company will use its commercially reasonable efforts to ensure Trust II remains a statutory trust, except in connection with a distribution of debt securities to the holders of the Trust II securities in liquidation of Trust II, the redemption of all Trust II’s securities or mergers, consolidations or incorporation, each as permitted by Trust II’s declaration of trust; • to continue to be classified as a grantor trust for U.S. federal income tax purposes; and • the Company will ensure each holder of Trust II’s preferred securities is treated as owning an undivided beneficial interest in the junior subordinated debentures. At December 31, 2017 and 2016 , the Company was in compliance with the above covenants. So long as the Company is not in default in the payment of interest on the junior subordinated debentures, the Company has the right under the indenture to defer payments of interest for up to 20 consecutive quarterly periods. The Company does not currently intend to exercise its right to defer interest payments on the junior debentures issued to Trust II. If the Company defers interest payments, it would be subject to certain restrictions relating to the payment of dividends on or purchases of its capital stock and payments on its debt securities ranking equal with or junior to the junior subordinated debentures. Boston Private Capital Trust I Junior Subordinated Debentures In 2004, the Company and Boston Private Capital Trust I, a Delaware statutory trust (“Trust I”), entered into a Purchase Agreement and an option, which was exercised in 2004, for the sale of a combined total of $105 million of convertible trust preferred securities to be issued by Trust I and guaranteed by the Company on a subordinated basis. The convertible trust preferred securities have a liquidation amount of $50.00 per security, pay interest quarterly and have a fixed distribution rate of 4.875% . The quarterly distributions are cumulative. The junior subordinated convertible debentures will mature on October 1, 2034 . As of December 31, 2017 , there was an immaterial amount remaining outstanding of the Trust I convertible trust preferred securities. The Company’s investment in Trust I was $3.2 million at both December 31, 2017 and 2016 .

Noncontrolling Interests

Noncontrolling Interests	12 Months Ended
	Dec. 31, 2017
NONCONTROLLING INTERESTS [Abstract]
Noncontrolling Interest Disclosure [Text Block]	NONCONTROLLING INTERESTS At the Company, noncontrolling interests consist of equity owned by management of the Company’s respective majority-owned affiliates. Net income attributable to noncontrolling interests in the consolidated statements of operations represents the net income allocated to the noncontrolling interest owners of the affiliates. Net income allocated to the noncontrolling interest owners was $4.5 million , $4.2 million , and $4.4 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. On the consolidated balance sheets, noncontrolling interests are included as the sum of the capital and undistributed profits allocated to the noncontrolling interest owners. Typically, this balance is included in a company’s permanent shareholders’ equity in the consolidated balance sheets. When the noncontrolling interest owners’ rights include certain redemption features, as described in ASC 480, Distinguishing Liabilities from Equity , such redeemable noncontrolling interests are classified as mezzanine equity and are not included in permanent shareholders’ equity. Due to the redemption features of the noncontrolling interests discussed in this footnote, the Company had redeemable noncontrolling interests held in mezzanine equity in the accompanying consolidated balance sheets of $17.5 million and $17.0 million at December 31, 2017 and 2016 , respectively. The aggregate amount of such redeemable noncontrolling equity interests are recorded at the estimated maximum redemption values, as discussed below. In addition, as discussed below, the Company had $5.2 million and $4.2 million in noncontrolling interests included in permanent shareholders’ equity at December 31, 2017 and 2016 , respectively. Each non-wholly owned affiliate operating agreement provides the Company and/or the noncontrolling interests with contingent call or put redemption features used for the orderly transfer of noncontrolling equity interests between the affiliate noncontrolling interest owners and the Company at either a contractually predetermined fair value, multiple of EBITDA, or fair value. The Company may liquidate these noncontrolling interests in cash, shares of the Company’s common stock, or other forms of consideration dependent on the operating agreement. Generally, these put and call redemption features refer to shareholder rights of both the Company and the noncontrolling interest owners of the Company’s majority-owned affiliate companies. The affiliate company noncontrolling interests generally take the form of limited liability company (LLC) units, profits interests, or common stock (collectively, the “noncontrolling equity interests”). In most circumstances, the put and call redemption features generally relate to the Company’s right and, in some cases, obligation to purchase and the noncontrolling equity interests’ right to sell their equity interests. There are various events that could cause the puts or calls to be exercised, such as a change in control, death, disability, retirement, resignation or termination. The puts and calls are generally to be exercised at the then fair value or a contractually agreed upon approximation thereof. The terms of these rights vary and are governed by the respective individual operating and legal documents. The following table presents, by affiliate, the noncontrolling interests included as redeemable noncontrolling interests and noncontrolling interests in mezzanine and permanent equity, respectively, at the periods indicated: December 31, 2017 December 31, 2016 (In thousands) Anchor $ 9,761 $ 10,934 BOS 8,057 6,782 DGHM (1) 4,829 3,417 Total $ 22,647 $ 21,133 Redeemable noncontrolling interests $ 17,461 $ 16,972 Noncontrolling interests $ 5,186 $ 4,161 _____________ (1) Only includes redeemable noncontrolling interests. The following is a summary, by individual affiliate, of the terms of the put and call options: Anchor The Company, through its acquisition of Anchor, acquired approximately an 80% interest in each of Anchor and Anchor Russell on June 1, 2006. Effective January 1, 2013, Anchor Russell merged into Anchor, with Anchor as the surviving entity. Anchor management, employees, and certain retired employees own the remaining noncontrolling equity interests of the firm, approximately 20%. The Anchor operating agreement describes a process for the orderly transfer of noncontrolling equity interests between the Company and the Anchor noncontrolling interest owners at a contractually agreed upon value, with appraisal rights for all parties. Certain events, such as death, disability, retirement, resignation, or termination, may result in repurchase of the noncontrolling equity interests by the Company at the then contractually agreed upon value. The Anchor agreement provides a formulaic mechanism to determine the then value of the noncontrolling equity interests. These noncontrolling equity interests have a five-year vesting period. Beginning six months after vesting, a holder of noncontrolling equity interests may put up to 10% of his or her outstanding equity interests annually to the Company. The six-month holding period ensures the risks and rewards of ownership are transferred to the holder of the noncontrolling equity interests. Holders of noncontrolling equity interests must retain 50% of their total outstanding units until such time as they leave the firm. In 2013, the Company sold certain repurchased noncontrolling interests to employees at Anchor with modified contingent call and put redemption features. These modified noncontrolling interests have the same terms and conditions as the previously issued noncontrolling interests with the exception that they require the approval of the Company’s CEO in order to be exercised. Therefore, these modified noncontrolling interests are not considered to be mandatorily redeemable and are not included in the redeemable noncontrolling interests within mezzanine equity, but rather within permanent equity. In December 2017, the Company entered into an agreement to sell its interest in Anchor. The transaction is expected to close in the first quarter of 2018. While the assets and liabilities of Anchor are classified as held for sale on the Company’s consolidated balance sheet as of December 31, 2017, equity interests, including noncontrolling interests, and the related call and put redemption features remain in place. The maximum redemption value, based on the contractually determined maximum redemption value formula, to repurchase the remaining approximately 20% of Anchor’s noncontrolling equity interests was approximately $9.8 million and $10.9 million as of December 31, 2017 and 2016 , respectively. Of the $9.8 million of noncontrolling equity interests at December 31, 2017 , $2.9 million is included in permanent equity and the remainder is included in mezzanine equity. Of the $10.9 million of noncontrolling equity interests at December 31, 2016 , $2.0 million was included in permanent equity and the remainder was included in mezzanine equity. BOS The Company acquired approximately a 70% interest in BOS through a series of purchases dating back to February 5, 2004. The remaining approximate 30% is owned by BOS principals and certain retired principals. The BOS operating agreement describes a procedure for the orderly transfer of noncontrolling equity interests between the BOS noncontrolling interest owners and the Company at the then fair value, with appraisal rights for all parties. Certain events, such as death, disability, retirement, resignation, or voluntary termination, subject to the vesting period, will result in repurchase of the noncontrolling equity interests by the Company at the then fair value, unless another noncontrolling interest owner opts to purchase the noncontrolling equity interests in question. These noncontrolling equity interests have vesting periods of up to seven years. Immediately after vesting, a holder of noncontrolling equity interests may put up to the greater of 10% of his or her outstanding equity interests or 1% of total outstanding equity interests in BOS annually to the Company. Any unexercised portion of the annual put option can be carried forward to future years, provided that noncontrolling interest owners retain approximately 50% of their total outstanding units until such time as they leave the firm. In 2015, the Company entered into an updated operating agreement with BOS which provides for a certain portion of the BOS noncontrolling interest owners’ to include modified contingent call and put redemption features. These modified noncontrolling interests have the same terms and conditions as the previously issued noncontrolling interests with the exception that they require the approval of the Company’s CEO in order to be exercised. Therefore, these modified noncontrolling interests are not considered to be mandatorily redeemable and are not included in the redeemable noncontrolling interests within mezzanine equity, but rather within permanent equity. The maximum redemption value, based on fair value, to repurchase the remaining approximately 30% of BOS’ noncontrolling equity interests is approximately $8.1 million and $6.8 million as of December 31, 2017 and 2016 , respectively. Of the $8.1 million of noncontrolling equity interests at December 31, 2017 , $2.3 million is included in permanent equity and the remainder is included in mezzanine equity. Of the $6.8 million of noncontrolling equity interests at December 31, 2016 , $2.2 million was included in permanent equity and the remainder was included in mezzanine equity. DGHM The Company acquired an 80% interest in DGHM on February 6, 2004. DGHM management and employees own the remaining 20% interest in DGHM. The DGHM operating agreement describes a process for the orderly transfer of noncontrolling equity interests between the Company and the DGHM noncontrolling interest owners at a contractually agreed upon value, with appraisal rights for all parties. Certain events, such as a change in control, death, disability, retirement, resignation or termination, may result in repurchase of the noncontrolling equity interests by the Company at the then contractually agreed upon value. The DGHM operating agreement provides a formulaic mechanism to determine the then value of the noncontrolling equity interests. These noncontrolling equity interests have a five-year vesting period. Beginning six months after vesting, a holder of noncontrolling equity interests may put up to between 10% and 20% of his or her outstanding units annually to the Company. The six-month holding period ensures the risks and rewards of ownership are transferred to the holder of the noncontrolling equity interests. Beginning in December 2009, the Company has an annual call right under which it may elect to repurchase between 10% and 20% of the non-management and management members’ vested units. No more than 40% of the outstanding noncontrolling equity interests’ units can be put in any one year. Certain key members of DGHM management are contractually obligated to retain 50% of their noncontrolling equity interests until such time as they leave the firm. The maximum redemption value, based on the contractually determined maximum redemption value formula, to repurchase the remaining 20% of DGHM’s noncontrolling equity interests is approximately $4.8 million and $3.4 million as of December 31, 2017 and 2016 , respectively. The following tables present an analysis of the Company’s redeemable noncontrolling interests for the periods indicated: Year ended December 31, 2017 December 31, 2016 December 31, 2015 Redeemable noncontrolling interests Noncontrolling interests Redeemable noncontrolling interests Noncontrolling interests Redeemable noncontrolling interests Noncontrolling interests (In thousands) Noncontrolling interests at beginning of period $ 16,972 $ 4,161 $ 18,088 $ 3,393 $ 20,905 $ 386 Net income attributable to noncontrolling interests 3,354 1,114 3,204 953 3,575 832 Distributions (3,277 ) (1,083 ) (3,112 ) (942 ) (4,189 ) (422 ) Purchases/ (sales) of ownership interests 235 85 (765 ) (134 ) (1,666 ) 419 Transfers of ownership interests from mezzanine to permanent equity — — — — (1,652 ) 1,652 Amortization of equity compensation 413 935 449 747 — 472 Adjustments to fair value (236 ) (26 ) (892 ) 144 1,115 54 Noncontrolling interests at end of period $ 17,461 $ 5,186 $ 16,972 $ 4,161 $ 18,088 $ 3,393 Impact on EPS from Certain Changes in Redemption Value To the extent that the increase in the estimated maximum redemption amounts exceeds the net income attributable to the noncontrolling interests, such excess may reduce net income attributable to the Company’s common shareholders for purposes of the Company’s EPS computations depending upon how the maximum redemption value is calculated. In cases where the maximum redemption value is calculated using a contractually determined value or predefined formula, such as a multiple of EBITDA, there may be a reduction to the net income attributable to the Company’s common shareholders for purposes of the Company’s EPS computations. However, in cases where maximum redemption value is calculated using the then fair value, there is no effect on EPS. Fair value can be derived through an enterprise value using market observations of comparable firms, a discounted cash flow analysis, or a combination of the two, among other things, rather than a contractually predefined formula or multiple of EBITDA.

Equity

Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	EQUITY Preferred Stock The Company has 2,000,000 depositary shares outstanding at both December 31, 2017 and December 31, 2016 (the “Depositary Shares”). Each Depositary Share represents a 1/40th interest in a share of the Company’s 6.95% Non-Cumulative Perpetual Preferred Stock, Series D, par value $1.00 per share and liquidation preference of $1,000 per share (the “Series D preferred stock”). This represents the entire $47.8 million balance of preferred stock on the Company’s balance sheet at both December 31, 2017 and December 31, 2016 . The ability of the Company to declare and pay dividends on, or purchase, redeem or otherwise acquire, shares of its preferred stock or any securities of the Company that rank junior to the Series D preferred stock is subject to certain restrictions in the event that the Company does not declare and pay (or set aside) dividends on the Series D preferred stock for the last preceding quarterly dividend period. The Company may redeem the Series D preferred stock on any dividend payment date on or after June 15, 2018; or within 90 days of a change, proposed change, administrative decision, or re-interpretation in the laws, regulations, or guidelines regarding the regulatory capital treatment of the Series D preferred stock. Common Stock The Company has 170 million shares of common stock authorized for issuance. At December 31, 2017 , it had 84,208,538 shares outstanding and 85,791,462 shares available for future issuance, including shares reserved for future issuance pursuant to the Company’s stock-based compensation plans, as discussed in Part II. Item 8. “Financial Statements and Supplementary Data - Note 18: Employee Benefits.” At December 31, 2016 , it had 83,731,769 shares outstanding and 86,268,231 shares available for future issuance. Warrants to Purchase Common Stock The Company currently has one class of warrants to purchase common stock outstanding. These warrants were initially issued to the U.S. Department of the Treasury (the “Treasury”) (the “TARP warrants”). The following table summarizes the terms of the TARP warrant agreement outstanding at December 31, 2017 : Name of warrants Number of warrants Original warrant share number Current warrant share number (2) Original exercise price of warrants Current exercise price of warrants (2) Date issued Expiration date TARP Warrants (1) 1,692,755 1.00 1.14 $8.000 $7.011 11/21/2008 11/21/2018 ___________________ (1) The TARP warrants, while initially issued to the Treasury, were purchased from the Treasury by unrelated third parties at a market rate. (2) Per the terms of the TARP warrant agreement, the exercise price and number of shares issuable upon exercise may be adjusted ratably for dividends paid on the Company’s common stock that exceed the dividend rate at the time the warrants were issued, at which time the Company paid quarterly dividends of $0.01 per share. The current warrant share number and current exercise price of the warrant reflect the warrant as adjusted for common stock dividends through February 2, 2018, the latest dividend record date prior to the filing of this Annual Report. Accumulated Other Comprehensive Income Other comprehensive income/ (loss) represents the change in equity of the Company during a year from transactions and other events and circumstances from non-shareholder sources. It includes all changes in equity during a year except those resulting from investments by shareholders and distributions to shareholders. The following table presents the Company’s comprehensive income/ (loss) and related tax effect for the years ended December 31, 2017 , 2016 , and 2015 : 2017 2016 2015 Pre- tax Tax effect Net of Tax Pre- Tax Net of Pre- Tax Net of (In thousands) Unrealized gain/ (loss) on securities available-for-sale Net gains/ (losses) arising during period $ 7,782 $ 3,063 $ 4,719 $ (18,913 ) $ (7,555 ) $ (11,358 ) $ (2,494 ) $ (1,145 ) $ (1,349 ) Less: Adjustment for realized gains/ (losses), net 376 154 222 521 190 331 236 97 139 Net change 7,406 2,909 4,497 (19,434 ) (7,745 ) (11,689 ) (2,730 ) (1,242 ) (1,488 ) Unrealized gain/ (loss) on cash flow hedges Net gains/ (losses) arising during period 325 135 190 (793 ) (332 ) (461 ) (2,642 ) (1,088 ) (1,554 ) Add: scheduled reclass and other 1,179 491 688 1,666 687 979 4,052 1,698 2,354 Net change 1,504 626 878 873 355 518 1,410 610 800 Unrealized gain/ (loss) on other Net gains/ (losses) arising during period 84 34 50 200 77 123 (193 ) (78 ) (115 ) Net change 84 34 50 200 77 123 (193 ) (78 ) (115 ) Total other comprehensive income/ (loss) 8,994 3,569 5,425 (18,361 ) (7,313 ) (11,048 ) (1,513 ) (710 ) (803 ) Net income attributable to the Company (1) 86,787 46,196 40,591 102,591 30,963 71,628 95,317 30,392 64,925 Total comprehensive income $ 95,781 $ 49,765 $ 46,016 $ 84,230 $ 23,650 $ 60,580 $ 93,804 $ 29,682 $ 64,122 ___________________ (1) Pre-tax net income attributable to the Company is calculated as income before income taxes, plus net income from discontinued operations, less net income attributable to noncontrolling interests. The following table presents a summary of the amounts reclassified from accumulated other comprehensive income/ (loss) for the years ended December 31, 2017 , 2016 , and 2015 : Description of component of accumulated other comprehensive income/ (loss) Year ended December 31, Affected line item in Statement of Operations 2017 2016 2015 (In thousands) Adjustment for realized gains/(losses) on securities available-for-sale, net: Pre-tax $ 376 $ 521 $ 236 Gain/ (loss) on sale of investments, net Tax expense/ (benefit) 154 190 97 Income tax expense Net $ 222 $ 331 $ 139 Net income attributable to the Company Net realized gain/ (loss) on cash flow hedges: Hedge related to junior subordinated debentures: Pre-tax $ — $ — $ 1,879 Interest expense on junior subordinated debentures Tax expense/ (benefit) — — 804 Income tax expense Net $ — $ — $ (1,075 ) Net income attributable to the Company Hedge related to deposits Pre-tax $ 1,179 $ 1,666 $ 2,173 Interest expense on deposits Tax expense/ (benefit) 491 687 894 Income tax expense Net $ (688 ) $ (979 ) $ (1,279 ) Net income attributable to the Company Total reclassifications for the period, net of tax $ (688 ) $ (979 ) $ (2,354 ) The following table presents the after-tax changes in the components of the Company’s accumulated other comprehensive income/ (loss) for the years ended December 31, 2017 , 2016 , and 2015 : Components of accumulated other comprehensive income/ (loss) Unrealized gain/ (loss) on securities available-for-sale Unrealized gain/ (loss) on cash flow hedges Unrealized gain/ (loss) on other Accumulated other comprehensive income/ (loss) (In thousands) Balance at December 31, 2014 $ 1,983 $ (1,923 ) $ (757 ) $ (697 ) Other comprehensive income/ (loss) before reclassifications (1,349 ) (1,554 ) (115 ) (3,018 ) Amounts reclassified from other comprehensive income/ (loss) (139 ) 2,354 — 2,215 Other comprehensive income/ (loss), net (1,488 ) 800 (115 ) (803 ) Balance at December 31, 2015 495 (1,123 ) (872 ) (1,500 ) Other comprehensive income/ (loss) before reclassifications (11,358 ) (461 ) 123 (11,696 ) Amounts reclassified from other comprehensive income/ (loss) (331 ) 979 — 648 Other comprehensive income/ (loss), net (11,689 ) 518 123 (11,048 ) Balance at December 31, 2016 (11,194 ) (605 ) (749 ) (12,548 ) Other comprehensive income/ (loss) before reclassifications 4,719 190 50 4,959 Amounts reclassified from other comprehensive income/ (loss) (222 ) 688 — 466 Other comprehensive income/ (loss), net 4,497 878 50 5,425 Reclassification due to the adoption of ASU 2018-02 (1,443 ) 59 (151 ) (1,535 ) Balance at December 31, 2017 $ (8,140 ) $ 332 $ (850 ) $ (8,658 )

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	EARNINGS PER SHARE Earnings Per Share (“EPS”) Basic EPS is computed by dividing net income attributable to common shareholders by the weighted average number of common shares outstanding during the year. Diluted EPS is determined in the same manner as basic EPS except that the number of shares is increased assuming exercise or contingent issuance of the options, warrants or other dilutive securities; and conversion of the convertible trust preferred securities. Additionally, when dilutive, interest expense (net of tax) related to the convertible trust preferred securities is added back to net income attributable to common shareholders. The calculation of diluted EPS excludes the potential dilution of common shares and the inclusion of any related expenses if the effect is antidilutive. The following tables present a reconciliation of the components of basic and diluted EPS computations for the three years ended December 31: For the year ended December 31, 2017 2016 2015 (In thousands, except share and per share data) Basic earnings per share - Numerator: Net income from continuing operations $ 40,189 $ 70,244 $ 62,921 Less: Net income attributable to noncontrolling interests 4,468 4,157 4,407 Net income from continuing operations attributable to the Company 35,721 66,087 58,514 Decrease/ (increase) in noncontrolling interests’ redemption values (1) (1,412 ) (588 ) 464 Dividends on preferred stock (3,475 ) (3,475 ) (3,475 ) Total adjustments to income attributable to common shareholders (4,887 ) (4,063 ) (3,011 ) Net income from continuing operations attributable to common shareholders, treasury stock method (2) 30,834 62,024 55,503 Net income from discontinued operations (2) 4,870 5,541 6,411 Net income attributable to common shareholders, treasury stock method (2) $ 35,704 $ 67,565 $ 61,914 Basic earnings per share - Denominator: Weighted average basic common shares outstanding 82,430,633 81,264,273 80,885,253 Per share data - Basic earnings per share from: Continuing operations $ 0.37 $ 0.76 $ 0.69 Discontinued operations $ 0.06 $ 0.07 $ 0.08 Total attributable to common shareholders $ 0.43 $ 0.83 $ 0.77 For the year ended December 31, 2017 2016 2015 (In thousands, except share and per share data) Diluted earnings per share - Numerator: Net income from continuing operations attributable to common shareholders, after assumed dilution (2) $ 30,834 $ 62,024 $ 55,503 Net income from discontinued operations 4,870 5,541 6,411 Net income attributable to common shareholders, after assumed dilution $ 35,704 $ 67,565 $ 61,914 Diluted earnings per share - Denominator: Weighted average basic common shares outstanding 82,430,633 81,264,273 80,885,253 Dilutive effect of: Stock options, performance-based and time-based restricted stock, and performance-based and time-based restricted stock units, and other dilutive securities (2), (3) 1,313,953 1,002,153 1,301,448 Warrants to purchase common stock (3) 1,057,979 942,700 1,206,389 Dilutive common shares 2,371,932 1,944,853 2,507,837 Weighted average diluted common shares outstanding (2), (3) 84,802,565 83,209,126 83,393,090 Per share data - Diluted earnings per share from: Continuing operations $ 0.36 $ 0.74 $ 0.66 Discontinued operations $ 0.06 $ 0.07 $ 0.08 Total attributable to common shareholders $ 0.42 $ 0.81 $ 0.74 Dividends per share declared and paid on common stock $ 0.44 $ 0.40 $ 0.36 _____________________ (1) See Part II. Item 8. “Financial Statements and Supplementary Data - Note 14: Noncontrolling Interests” for a description of the redemption values related to the redeemable noncontrolling interests. In accordance with ASC 480, Distinguishing Liabilities from Equity (“ASC 480”), an increase in redemption values from period to period reduces income attributable to common shareholders. Decreases in redemption value from period to period increase income attributable to common shareholders, but only to the extent that the cumulative change in redemption value remains a cumulative increase since adoption of this standard in the first quarter of 2009. (2) The Company presents its EPS based on the treasury stock method. The Company reverted to the treasury stock presentation from the two-class presentation due to the immaterial number of participating shares outstanding as of March 31, 2016. There is no difference between the calculation of EPS based on the treasury stock method and the calculation of EPS based on the two-class method for the year ended December 31, 2017. If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2016. Net income attributable to common shareholders would have been reduced by an additional $4 thousand , for the year ended December 31, 2016. The allocation of net income to participating securities would have been $8 thousand for the year ended December 31, 2016, reducing net income attributable to common shareholders by a total of $12 thousand for the same period. Basic EPS would not change. Weighted average diluted shared outstanding would have been reduced by 7,185 shares for the year ended December 31, 2016. Diluted EPS would not change. If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2015. Net income attributable to common shareholders would have been reduced by an additional $90 thousand for the year ended December 31, 2015, and the allocation of net income to participating securities would have been $92 thousand for the same period, reducing net income attributable to common shareholders by a total of $182 thousand , for the same period. Total basic EPS and basic EPS from continuing operations would each decrease by $0.01 per share for the year ended December 31, 2015. Weighted average diluted shares outstanding would have been reduced by 167,937 shares for the same period. Diluted EPS would not change. (3) The diluted EPS computations for the years ended December 31, 2017 , 2016 , and 2015 do not assume the conversion, exercise or contingent issuance of the following shares for the following periods because the result would have been antidilutive for the periods indicated. As a result of the anti-dilution, the potential common shares excluded from the diluted EPS computation are as follows: For the year ended December 31, 2017 2016 2015 Shares excluded due to anti-dilution (treasury stock method): (In thousands) Potential common shares from: Convertible trust preferred securities (a) 1 1 1 Total shares excluded due to anti-dilution 1 1 1 For the year ended December 31, 2017 2016 2015 Shares excluded due to exercise price exceeding the average market price of common shares during the period (total outstanding): (In thousands) Potential common shares from: Options, restricted stock, or other dilutive securities (b) 67 270 548 Total shares excluded due to exercise price exceeding the average market price of common shares during the period 67 270 548 (a) If the effect of the conversion of the trust preferred securities would have been dilutive, an immaterial amount of interest expense, net of tax, related to the convertible trust preferred securities would have been added back to net income attributable to common shareholders for the diluted EPS computation for the years presented. (b) Options to purchase shares of common stock, non-participating performance- and certain time-based restricted stock, and other dilutive securities that were outstanding at period ends were not included in the computation of diluted EPS or in the above anti-dilution table because their exercise or conversion prices were greater than the average market price of the common shares during the respective periods.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Income Taxes [Text Block]	INCOME TAXES The components of income tax expense for continuing operations for the years ended December 31, 2017 , 2016 , and 2015 are as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Current expense: Federal $ 17,176 $ 20,237 $ 25,631 State 6,509 7,778 9,183 Total current expense 23,685 28,015 34,814 Deferred expense/(benefit): Federal 19,820 1,976 (3,185 ) State 2,691 972 (1,237 ) Total deferred expense/(benefit) 22,511 2,948 (4,422 ) Income tax expense $ 46,196 $ 30,963 $ 30,392 Income tax expense attributable to income from continuing operations differs from the amounts computed by applying the Federal statutory rate to pre-tax income from continuing operations. Reconciliations between the Federal statutory income tax rate of 35% to the effective income tax rate for the years ended December 31, 2017 , 2016 , and 2015 are as follows: Year Ended December 31, 2017 2016 2015 Statutory Federal income tax rate 35.0 % 35.0 % 35.0 % Increase/ (decrease) resulting from: Re-measurement of deferred tax assets and liabilities 13.7 % — % — % Nondeductible goodwill 10.1 % — % — % Tax-exempt interest, net (10.3 )% (7.5 )% (7.1 )% State and local income tax, net of Federal tax benefit 6.9 % 5.6 % 5.5 % Tax credits (3.1 )% (2.2 )% (1.9 )% Investments in affordable housing projects 2.2 % 0.9 % 0.9 % Noncontrolling interests (1.5 )% (1.4 )% (1.6 )% Out-of-period adjustment — % — % 1.3 % Other, net 0.5 % 0.2 % 0.5 % Effective income tax rate 53.5 % 30.6 % 32.6 % On December 22, 2017, H.R. 1, the Tax Act, was enacted by the U.S. government. Substantially all of the provisions of the Tax Act are effective as of January 1, 2018. The Tax Act includes significant changes to the Internal Revenue Code of 1986, as amended, including amendments which significantly change the taxation of business entities. The more significant changes in the Tax Act that impact the Company are the reduction in the federal corporate tax rate from 35% to 21% and the changes to the deductibility of executive compensation, both of which are effective as of January 1, 2018. Under ASC 740, the tax effects of changes in tax laws must be recognized in the period in which the law is enacted, or December 22, 2017 for the Tax Act. ASC 740 also requires deferred tax assets and liabilities to be measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. The Company re-measured its deferred tax assets and liabilities at the 21% federal corporate tax rate, reevaluated its investments in affordable housing projects using the 21% federal corporate tax rate, and reduced its deferred tax assets associated with executive compensation that is no longer deductible. As a result of these changes, the Company recorded a federal tax expense of $12.9 million in the fourth quarter of 2017. The staff of the SEC has recognized the complexity of reflecting the impacts of the Tax Act, and on December 22, 2017 issued guidance in Staff Accounting Bulletin No. 118 (“SAB 118”) which clarifies accounting for income taxes under ASC 740 if information is not yet available or complete and provides for up to a one year period in which to complete the required analyses and accounting. SAB 118 describes three scenarios associated with a company’s status of accounting for income tax reform: (1) a company is complete with its accounting for certain effects of tax reform, (2) a company is able to determine a reasonable estimate for certain effects of tax reform and records that estimate as a provisional amount, or (3) a company is not able to determine a reasonable estimate and therefore continues to apply ASC 740, based on the provisions of the tax laws that were in effect immediately prior to the Tax Act being enacted. The Company completed its accounting of the effects of the Tax Act which have been reflected in the December 31, 2017 financial statements. During the third quarter of 2015, the Company reevaluated its executive compensation plans and identified certain executive compensation that was previously treated as fully deductible was non-deductible. The correction resulted in $1.2 million of additional federal tax expense and $0.2 million of additional state tax, net of federal tax benefit, that was related to prior years. After evaluating the quantitative and qualitative aspects of the correction, the Company determined that previously issued consolidated financial statements were not materially misstated and, as a result, recorded the correction in 2015. On April 13, 2015, New York City enacted legislation that requires corporations that are engaged in unitary business operations to file combined returns with their affiliates for tax years beginning on or after January 1, 2015. Starting in 2015, all of the Company’s affiliates are included in the Company’s New York City tax return instead of just those affiliates with nexus to New York City. The Company incorporated the impact of these New York City tax law changes in 2015 due to the law being enacted in 2015. The Company adjusted the New York City apportionment percentages for purposes of measuring deferred tax assets and liabilities that will reverse after the effective date. As a result of these changes, the Company recorded a state tax benefit of $0.5 million , net of federal tax, in 2015. The components of gross deferred tax assets and gross deferred tax liabilities at December 31, 2017 and 2016 are as follows: December 31, 2017 2016 (In thousands) Gross deferred tax assets: Allowance for loan and OREO losses $ 22,782 $ 35,545 Interest on nonaccrual loans 295 548 Stock compensation 3,156 6,079 Deferred and accrued compensation 11,822 19,801 Contingent payments 1,236 1,868 Unrealized loss on investments 3,345 8,264 Other 1,437 905 Gross deferred tax assets 44,073 73,010 Total deferred tax assets 44,073 73,010 Gross deferred tax liabilities: Deferred income on repurchase of debt 832 2,692 Goodwill and acquired intangible assets 12,246 12,929 Fixed assets 991 67 Prepaid expenses 347 611 Other 626 1,251 Total gross deferred tax liabilities 15,042 17,550 Net deferred tax asset $ 29,031 $ 55,460 Of the $26.4 million net decrease in the Company’s net deferred tax asset during 2017, $22.5 million was recognized as deferred income tax expense, $0.3 million was recognized as deferred income tax expense for discontinued operations, and $3.6 million was recognized as a decrease to shareholders’ equity. The $22.5 million deferred income tax expense includes $11.8 million from the re-measurement of deferred tax assets and liabilities due to the reduction in the federal corporate tax rate from 35% to 21% effective January 1, 2018 and $0.7 million from the reduction of deferred tax assets associated with executive compensation that is no longer deductible as a result of the Tax Act. In accordance with ASC 740, deferred tax assets are to be reduced by a valuation allowance if, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The realization of the tax benefit depends upon the existence of sufficient taxable income of the appropriate character within the carry-forward periods. The Company believes that it is more likely than not that the net deferred tax asset as of December 31, 2017 will be realized, based primarily upon the ability to generate future taxable income. Other positive evidence to support the realization of the Company’s net deferred tax asset includes: • The Company had cumulative pre-tax income, as adjusted for permanent book-to-tax differences, in the period 2015 through 2017. • Certain tax planning strategies are available to the Company, such as reducing investments in tax-exempt securities. • The Company has not had any operating loss or tax credit carryovers expiring unused in recent years. A reconciliation of the beginning and ending gross amount of unrecognized tax benefits under the provisions of ASC 740-10 is as follows: 2017 2016 2015 (In thousands) Balance at January 1 $ 974 $ 1,022 $ 1,067 Additions based on tax positions related to the current year 183 160 163 Additions based on tax positions taken in prior years 227 — — Decreases based on the expiration of statute of limitations (359 ) (208 ) (208 ) Balance at December 31 $ 1,025 $ 974 $ 1,022 The Company does not currently believe there is a reasonable possibility of any significant change to unrecognized tax benefits within the next twelve months. Excluded from the gross amount of unrecognized tax benefits for the years ended December 31, 2017, 2016, and 2015 are the federal tax benefits associated with the gross amount of state unrecognized tax benefits which, if recognized, would affect the effective tax rate. The net amount of unrecognized tax benefit which, if recognized, would affect the effective tax rate is $0.9 million at December 31, 2017 and $0.8 million at December 31, 2016 and 2015. The Company classifies interest and penalties, if applicable, related to unrecognized tax benefits as a component of income tax expense in the consolidated statements of operations. Interest and penalties recognized as part of the Company’s income tax expense was immaterial for the years ending December 31, 2017, 2016, and 2015. The accrued amounts for interest and penalties were immaterial as of December 31, 2017, 2016, and 2015. Federal income tax returns remain subject to examination by the Internal Revenue Service for all tax years subsequent to 2013. The examinations by the Internal Revenue Service for the tax years ended December 31, 2009 and December 31, 2012 were settled in August 2015 and December 2017, respectively. The resolution of these examinations did not have a significant impact on the effective tax rate. State income tax returns for the Company’s major tax jurisdictions of California, Florida, Massachusetts, and New York have either been examined or remain subject to examination for all the tax years subsequent to 2013. The examination by the State of New York for the tax year ended December 31, 2012 was settled in February 2015 and the examinations by the State of New York for the tax years ended December 31, 2013 and 2014 were settled in June 2017. The resolution of these examinations did not have a significant impact on the effective tax rate.

Employee Benefits Employee Bene

Employee Benefits Employee Benefits (Notes)	12 Months Ended
	Dec. 31, 2017
EMPLOYEE BENEFITS [Abstract]
Compensation and Employee Benefit Plans [Text Block]	EMPLOYEE BENEFITS Employee 401(k) Profit Sharing Plan The Company established a corporate-wide 401(k) Profit Sharing Plan (the “401(k) Plan”) for the benefit of the employees of the Company and its affiliates, which became effective on July 1, 2002. The 401(k) Plan is a 401(k) savings and retirement plan that is designed to qualify as an ERISA section 404(c) plan. Generally, employees who are at least twenty-one (21) years of age are eligible to participate in the plan on their date of hire. Employee contributions may be matched based on a predetermined formula and additional discretionary contributions may be made. 401(k) Plan expense was $3.3 million , $3.0 million , and $2.8 million , in the years ended December 31, 2017 , 2016 , and 2015 , respectively. Salary Continuation Plans The Bank maintains a salary continuation plan for certain former officers in the Bank’s San Francisco Bay Area market. The officers became eligible for benefits under the salary continuation plan if they reached a defined retirement age while working for the Bank. The Bank also has a deferred compensation plan for certain former directors of the former private banking affiliate in the San Francisco Bay Area that was merged into the Bank. The compensation expense relating to each contract is accounted for individually. The expense relating to these plans was $0.1 million for each of the years ended December 31, 2017 , 2016 , and 2015 . The amount recognized in other liabilities in the consolidated balance sheets was $1.0 million and $1.1 million at December 31, 2017 and 2016 , respectively. The Bank has purchased life insurance contracts to help fund these plans. The Bank has single premium life insurance policies with cash surrender values totaling $6.1 million and $6.3 million , which are included in other assets in the consolidated balance sheets, as of December 31, 2017 and 2016 , respectively. The Bank also maintains a salary continuation plan for certain former officers of the Bank’s Southern California market. The plan provides for payments to the participants at the age of retirement. The expense relating to these plans was $0.1 million for each of the years ended December 31, 2017 , 2016 , and 2015 . The net amount recognized in other liabilities in the consolidated balance sheets was $1.7 million and $1.9 million at December 31, 2017 and 2016 , respectively. The Bank has purchased life insurance contracts to help fund these plans. These life insurance policies have cash surrender values totaling $4.9 million and $4.8 million at December 31, 2017 and 2016 , respectively, which are included in other assets in the consolidated balance sheets. Deferred Compensation Plan The Company offers a deferred compensation plan (the “Deferred Compensation Plan”) that enables certain executives to elect to defer a portion of their compensation. The amounts deferred are excluded from the employee’s taxable income and are not deductible for income tax purposes by the Company until paid. The net deferred amount related to the Deferred Compensation Plan in other liabilities in the consolidated balance sheets was $7.1 million and $6.1 million at December 31, 2017 and 2016 , respectively. Increases and decreases in the value of the Deferred Compensation Plan are recognized as compensation expense in the consolidated statements of operations. The expense relating to the Deferred Compensation Plan was an expense of $0.9 million , an expense of $0.6 million , and an expense credit of $0.1 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The Company has adopted a special trust for the Deferred Compensation Plan called a Rabbi Trust. A Rabbi Trust is an arrangement that is used to accumulate assets that may be used to “fund” the Company’s obligation to pay benefits under the Deferred Compensation Plan. However, to prevent immediate taxation to the executives who participate in the Deferred Compensation Plan, the amounts placed in the Rabbi Trust must remain subject to the claims of the Company’s creditors. The investments chosen by the participants in the Deferred Compensation Plan are mirrored by the Rabbi Trust as a way to minimize the earnings volatility of the Deferred Compensation Plan. The net amount recognized in other assets in the consolidated balance sheets was $7.1 million and $6.1 million at December 31, 2017 and 2016 , respectively. Increases and decreases in the value of the Rabbi Trust are recognized in other income in the consolidated statement of operations. The income relating to this plan was a gain of $0.9 million , a gain of $0.6 million , and a loss of $0.1 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Stock-Based Incentive Plans At December 31, 2017 , the Company has three stock-based compensation plans. These plans encourage and enable the officers, employees, and non-employee directors of the Company to acquire a proprietary interest in the Company. The 2009 Stock Option and Incentive Plan (the “2009 Plan”), replaced the Company’s 2004 Stock Option and Incentive Plan. Under the 2009 Plan, the Company may grant options, stock appreciation rights, restricted stock, restricted stock units, unrestricted stock awards, performance share awards and dividend equivalent rights to its officers, employees, and non-employee directors of the Company for an amount not to exceed 2% of the total shares of common stock outstanding as of the last business day of the preceding fiscal year. The 2009 Plan provides for the authorization and issuance of 4,000,000 shares , along with any residual shares from previous plans. Under the 2009 Plan, the exercise price of each option shall not be less than 100% of the fair market value of the stock on the date the options are granted. Generally, options expire ten years from the date granted and vest over a three-year graded vesting period for officers and employees and a one-year or less period for non-employee directors. Stock grants generally vest over a three-year cliff vesting period . As of December 31, 2017 the maximum number of shares of stock reserved and available for issuance under the Plan was 2,414,842 . Under the Boston Private Financial Holdings, Inc. 2010 Inducement Stock Plan (the “Inducement Plan”), the Company may grant equity awards to new employees as an inducement to join the Company. The Company reserved 1,245,000 shares of the Company’s common stock for issuance under the Inducement Plan. The terms of the Inducement Plan are substantially similar to the terms of the 2009 Plan. In 2015, the Company issued an additional 22,936 shares under this plan in conjunction with an executive new hire. In 2016, the Company issued 37,177 shares under this plan in conjunction with executive new hires. In 2017, the Company issued 24,569 shares under this plan in conjunction with executive new hires. At December 31, 2017, the Inducement Plan had 727,491 reserved and available for issuance. The Company maintains a qualified Employee Stock Purchase Plan (“ESPP”). Under the ESPP, eligible employees may purchase common stock of the Company at 85 percent of the lower of the closing price of the Company’s common stock on the first or last day of a six month purchase period on The NASDAQ® Global Select Market. Employees pay for their stock purchases through payroll deductions at a rate equal to any whole percentage from 1 percent to 15 percent of after-tax earnings. Participants have a right to a full reimbursement of ESPP deferrals through the end of the offering period. Such a reimbursement would result in a reversal of the compensation expense previously recorded, attributed to that participant. The Company issues shares under the ESPP in January and July of each year. As of December 31, 2017, there were 637,442 shares available for issuance in the ESPP. There were 140,284 shares issued to participants under the qualified ESPP in 2017. Share-based payments recorded in salaries and benefits expense are as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Stock option and ESPP expense $ 480 $ 437 $ 518 Nonvested share expense 7,794 6,293 5,723 Subtotal 8,274 6,730 6,241 Tax benefit 3,188 2,574 2,367 Stock-based compensation expense, net of tax benefit $ 5,086 $ 4,156 $ 3,874 Stock Options A summary of option activity under the 2009 Plan for the year ended December 31, 2017 is as follows: Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term in Years Aggregate Intrinsic Value (in 000’s) Outstanding at December 31, 2016 656,400 $ 13.11 Granted — $ — Exercised 109,400 $ 8.21 Forfeited 12,798 $ 28.85 Expired 115,547 $ 29.73 Outstanding at December 31, 2017 418,655 $ 9.32 1.81 years $ 2,795.0 Exercisable at December 31, 2017 418,655 $ 9.32 1.81 years $ 2,795.0 The total intrinsic value of options exercised during the years ended December 31, 2017 , 2016 , and 2015 was $0.9 million , $1.5 million , and $0.7 million , respectively. As of December 31, 2017 , there was no unrecognized compensation cost related to stock option arrangements granted under the 2009 Plan. Restricted Stock A summary of the Company’s nonvested shares as of December 31, 2017 and changes during the year ended December 31, 2017 , including shares under both the 2009 Plan and the Inducement Plan, is as follows: Shares Weighted- Average Grant-Date Fair Value Nonvested at December 31, 2016 1,993,628 $ 12.16 Granted 485,263 $ 15.55 Vested 652,193 $ 12.28 Forfeited 100,789 $ 13.35 Nonvested at December 31, 2017 1,725,909 $ 13.03 The fair value of nonvested shares is determined based on the closing price of the Company’s stock on the grant date. The weighted-average grant-date fair value of shares granted during the years ended December 31, 2017 , 2016 , and 2015 was $15.55 , $11.58 , and $12.41 , respectively. At December 31, 2017 , there was $10.8 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements under the 2009 Plan and the Inducement Plan, combined. That cost is expected to be recognized over a weighted-average period of 2.01 years . The total fair value of shares that vested during the years ended December 31, 2017 , 2016 , and 2015 was $8.0 million , $5.3 million , and $5.3 million , respectively. Included in the restricted stock balances above are performance shares, which are granted to certain employees within the Company and are accounted for in the same manner as restricted stock. At December 31, 2017 , there were 811,286 performance shares outstanding, which could increase up to 1,558,411 shares. If the maximum number of performance shares is issued, the Company would incur an additional $9.8 million of compensation costs related to these additional 747,125 shares. The Company recognizes the expense for performance shares based upon the most likely outcome of shares to be issued based on current forecasts. Supplemental Executive Retirement Plans The Company has a non-qualified supplemental executive retirement plan (“SERP”) with a former executive officer of the Company. The SERP, which is unfunded, provides a defined cash benefit based on a formula using average compensation, years of service, and age at retirement of the executive. The estimated actuarial present value of the projected benefit obligation was $7.9 million and $8.2 million at December 31, 2017 and 2016 , respectively. The expense associated with the SERP was $0.4 million , $0.5 million , and $0.5 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The discount rate used to calculate the SERP liability was 3.60% , 4.10% , and 4.35% for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The Bank has a SERP with various former executives of the Pacific Northwest market. The SERP, which is unfunded, provides a defined cash benefit based on a formula using compensation, years of service, and age at retirement of the executives. The benefits for each executive under the plan are accrued until the full vesting age of 65. The actuarial present value of the projected benefit obligation was $3.2 million at both December 31, 2017 and 2016 . The expense associated with the SERP was $0.2 million for each of the years ended December 31, 2017 , 2016 , and 2015 . The discount rate used to calculate the SERP liability was 3.37% , 3.62% , and 3.81% , for the years ended December 31, 2017 , 2016 , and 2015 , respectively. KLS has a long term incentive plan (“LTIP”) with certain of its managing directors. This LTIP, which is unfunded, provides for a profit sharing based on current year results as well as a cash benefit at the time of separation of service. The cash payment at separation of service, which is determined based on the profit share and a multiple based on years of service, is payable in three equal annual installments following separation of service. The Company has accrued $8.1 million and $7.6 million at December 31, 2017 and 2016 , respectively, for future separation of service payments. The LTIP was effective beginning January 1, 2010. The expense associated with the LTIP was $0.5 million , $(0.2) million , and $1.3 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The discount rate used to calculate the SERP liability was 3.33% , 3.70% , and 3.90% for the years ended December 31, 2017 , 2016 , and 2015 , respectively.

Other Operating Expense

Other Operating Expense	12 Months Ended
	Dec. 31, 2017
OTHER OPERATING EXPENSE [Abstract]
Other Income and Other Expense Disclosure [Text Block]	OTHER OPERATING EXPENSE Major components of other operating expense are as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Employee travel and meals $ 3,910 $ 3,309 $ 2,874 Insurance 3,286 3,396 3,518 Other banking expenses 1,541 1,035 1,788 Publications and dues 1,028 984 870 Postage, express mail, and courier 974 967 1,007 Forms and supplies 890 836 1,241 OREO expenses 4 227 197 Provision/ (credit) for off-balance sheet loan commitments (24 ) (367 ) (271 ) Other 2,960 3,050 3,337 Total $ 14,569 $ 13,437 $ 14,561

Reportable Segments

Reportable Segments	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	REPORTABLE SEGMENTS Management Reporting The Company has four reportable segments: Private Banking, Wealth Management and Trust, Investment Management, and Wealth Advisory, and the Parent Company (Boston Private Financial Holdings, Inc.) (the “Holding Company”). The financial performance of the Company is managed and evaluated by these four areas. The segments are managed separately as a result of the concentrations in each function. The Company’s Segment Chief Executive Officers (“CEOs”) manage the segments and have full authority and responsibility for the performance and the allocation of resources within their respective segments. The Company’s CEO is the Company’s Chief Operating Decision Maker (“CODM”) . The day to day activities of the affiliates are managed by the affiliate CEOs, except in the Private Banking segment. The Company’s CEO is also the Bank’s CEO. The president of the Bank is the Private Banking Segment CEO and reports to the Company CEO. The Segment CEOs have authority with respect to the allocation of capital within their segments, management oversight responsibility, performance assessments, and overall authority and accountability for all of the affiliates, if any, within their segment. The Segment CEO for the non-banks communicates with the affiliate CEOs regarding profit and loss responsibility, strategic planning, priority setting and other matters. The Holding Company’s Chief Financial Officer reviews all affiliate financial detail with the CODM on a monthly basis. Description of Reportable Segments Private Banking The Private Banking segment operates primarily in three geographic markets: New England, the San Francisco Bay Area, and Southern California. The Bank currently conducts business under the name of Boston Private Bank & Trust Company in all markets. The Bank is chartered by The Commonwealth of Massachusetts and is insured by the FDIC. The Bank is principally engaged in providing private banking services to high net worth individuals, privately owned businesses and partnerships, and nonprofit organizations. In addition, the Bank is an active provider of financing for affordable housing, first-time homebuyers, economic development, social services, community revitalization and small businesses. Wealth Management and Trust The Wealth Management and Trust segment is comprised of the trust operations of the Bank and the operations of Boston Private Wealth. The segment offers investment management, wealth management, family office, and trust services to individuals, families, and institutions. The Wealth Management and Trust segment operates in New England; South Florida; California; and Madison, Wisconsin. Investment Management The Investment Management segment currently has two consolidated affiliates, including DGHM and Anchor, both of which are registered investment advisers (“RIAs”). After the expected sale of Anchor in the first quarter of 2018, DGHM will be the only affiliate in the Investment Management segment. The Investment Managers serve the needs of pension funds, endowments, trusts, foundations and select institutions, mutual funds and high net worth individuals and their families throughout the U.S. and abroad. The Investment Managers specialize in value-driven equity portfolios with products across the capitalization spectrum. The specific mix of products, services and clientele varies between affiliates. The Investment Managers are located in New England and New York, with one affiliate administrative office in South Florida. Wealth Advisory The Wealth Advisory segment has two consolidated affiliates, including KLS and BOS, both of which are RIAs and wealth management firms. The Wealth Advisors provide comprehensive, planning-based financial strategies to high net worth individuals and their families, and non-profit institutions. The services the firms offer include fee-only financial planning, tax planning, tax preparation, estate and insurance planning, retirement planning, charitable planning and intergenerational gifting and succession planning. The Wealth Advisors manage investments covering a wide range of asset classes for both taxable and tax-exempt portfolios. The Wealth Advisors are located in New York, Southern California and Northern California. Measurement of Segment Profit and Assets The accounting policies of the segments are the same as those described in Part II. Item 8. “Financial Statements and Supplementary Data - Note 1: Basis of Presentation and Summary of Significant Accounting Policies.” Reconciliation of Reportable Segment Items The following tables present a reconciliation of the revenues, profits, assets, and other significant items of reportable segments as of and for the year ended December 31, 2017 , 2016 , and 2015 . Interest expense on junior subordinated debentures is reported at the Holding Company. Year ended December 31, 2017 2016 2015 Private Banking (In thousands) Net interest income $ 227,280 $ 202,702 $ 189,501 Fees and other income 10,856 18,947 11,352 Total revenues 238,136 221,649 200,853 Provision/ (credit) for loan losses (7,669 ) (6,935 ) (1,555 ) Operating expense 149,008 125,116 116,575 Income before income taxes 96,797 103,468 85,833 Income tax expense (1) 43,356 33,120 27,844 Net income from continuing operations 53,441 70,348 57,989 Net income attributable to the Company $ 53,441 $ 70,348 $ 57,989 Assets $ 8,177,304 $ 7,816,671 $ 7,361,202 Amortization of intangibles $ — $ — $ 341 Depreciation $ 5,639 $ 4,477 $ 4,599 Year ended December 31, 2017 2016 2015 Wealth Management and Trust (In thousands) Fees and other income $ 45,813 $ 44,401 $ 53,336 Operating expense (2) 49,287 64,844 54,474 Income/ (loss) before income taxes (3,474 ) (20,443 ) (1,138 ) Income tax expense / (benefit) (1) (509 ) (8,279 ) (350 ) Net income/ (loss) from continuing operations (2,965 ) (12,164 ) (788 ) Net income/ (loss) attributable to the Company $ (2,965 ) $ (12,164 ) $ (788 ) Assets $ 74,128 $ 80,501 $ 80,088 Amortization of intangibles $ 2,882 $ 2,962 $ 2,428 Depreciation $ 1,331 $ 1,145 $ 772 Year ended December 31, 2017 2016 2015 Investment Management (In thousands) Net interest income $ 21 $ 16 $ 22 Fees and other income 45,551 44,443 45,687 Total revenues 45,572 44,459 45,709 Operating expense (3) 59,032 32,863 33,690 Income/ (loss) before income taxes (13,460 ) 11,596 12,019 Income tax expense (1) 3,811 3,789 3,956 Net income/ (loss) from continuing operations (17,271 ) 7,807 8,063 Noncontrolling interests 1,973 2,077 2,265 Net income/ (loss) attributable to the Company $ (19,244 ) $ 5,730 $ 5,798 Assets $ 66,614 $ 92,692 $ 92,642 Amortization of intangibles $ 2,524 $ 2,601 $ 2,956 Depreciation $ 248 $ 284 $ 286 Year ended December 31, 2017 2016 2015 Wealth Advisory (In thousands) Net interest income $ 124 $ 16 $ 6 Fees and other income 52,636 50,686 50,558 Total revenues 52,760 50,702 50,564 Operating expense 35,753 34,791 35,379 Income before income taxes 17,007 15,911 15,185 Income tax expense (1) 6,418 6,084 5,819 Net income from continuing operations 10,589 9,827 9,366 Noncontrolling interests 2,495 2,080 2,138 Net income attributable to the Company $ 8,094 $ 7,747 $ 7,228 Assets $ 77,747 $ 79,887 $ 79,543 Amortization of intangibles $ 195 $ 719 $ 986 Depreciation $ 888 $ 878 $ 864 Year ended December 31, 2017 2016 2015 Holding Company and Eliminations (In thousands) Net interest income $ (2,739 ) $ (2,296 ) $ (3,759 ) Fees and other income (4) (890 ) 310 236 Total revenues (3,629 ) (1,986 ) (3,523 ) Operating expense 6,856 7,339 15,063 Income/ (loss) before income taxes (10,485 ) (9,325 ) (18,586 ) Income tax expense/(benefit) (1) (6,880 ) (3,751 ) (6,877 ) Net income/(loss) from continuing operations (3,605 ) (5,574 ) (11,709 ) Noncontrolling interests — — 4 Discontinued operations (5) 4,870 5,541 6,411 Net income/(loss) attributable to the Company $ 1,265 $ (33 ) $ (5,302 ) Assets (including eliminations) $ (84,049 ) $ (99,277 ) $ (70,967 ) Depreciation $ — $ 54 $ 69 Year ended December 31, 2017 2016 2015 Total Company (In thousands) Net interest income $ 224,686 $ 200,438 $ 185,770 Fees and other income 153,966 158,787 161,169 Total revenues 378,652 359,225 346,939 Provision/ (credit) for loan losses (7,669 ) (6,935 ) (1,555 ) Operating expense 299,936 264,953 255,181 Income before income taxes 86,385 101,207 93,313 Income tax expense (1) 46,196 30,963 30,392 Net income from continuing operations 40,189 70,244 62,921 Noncontrolling interests 4,468 4,157 4,407 Discontinued operations (5) 4,870 5,541 6,411 Net income attributable to the Company $ 40,591 $ 71,628 $ 64,925 Assets $ 8,311,744 $ 7,970,474 $ 7,542,508 Amortization of intangibles $ 5,601 $ 6,282 $ 6,711 Depreciation $ 8,106 $ 6,838 $ 6,590 ___________________ (1) The Company’s effective tax rate for 2017 , 2016 , and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017 , 2016 , and 2015 . See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details. (2) Operating expense related to the Wealth Management and Trust segment includes restructuring expenses of $2.0 million , and $3.7 million for the years ending December 31, 2016 and 2015 respectively, and a goodwill impairment charge of $9.5 million for the year ended December 31, 2016. (3) Operating expense related to the Investment Management Segment includes a goodwill impairment charge of $24.9 million for the year ended December 31, 2017. (4) Fees and other income for the Holding Company includes a loss on the sale of $1.3 million for the year ended December 31, 2017 related to the classification of Anchor as held for sale. (5) The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017 , 2016 and 2015 of $4.9 million , $5.5 million , and $6.4 million , respectively.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value [Abstract]
Fair Value Disclosures [Text Block]	FAIR VALUE MEASUREMENTS Fair value is defined under GAAP as the exchange price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants on the measurement date. The Company determines the fair values of its financial instruments based on the fair value hierarchy established in ASC 820, Fair Value Measurements and Disclosures (“ASC 820”), which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. ASC 820 describes three levels of inputs that may be used to measure fair value. Financial instruments are considered Level 1 when valuation can be based on quoted prices in active markets for identical assets or liabilities. Level 2 financial instruments are valued using quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or models using inputs that are observable or can be corroborated by observable market data of substantially the full term of the assets or liabilities. Financial instruments are considered Level 3 when their values are determined using pricing models, discounted cash flow methodologies or similar techniques and at least one significant model assumption or input is unobservable and when determination of the fair value requires significant management judgment or estimation. The following tables present the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31, 2017 and 2016 , aggregated by the level in the fair value hierarchy within which those measurements fall: As of December 31, 2017 Fair value measurements at reporting date using: Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) (In thousands) Assets: Available-for-sale securities U.S. government and agencies $ 34,299 $ 34,096 $ 203 $ — Government-sponsored entities 302,501 — 302,501 — Municipal bonds 303,058 — 303,058 — Mortgage-backed securities 509,676 — 509,676 — Other 20,794 20,794 — — Total available-for-sale securities 1,170,328 54,890 1,115,438 — Derivatives - interest rate customer swaps 18,575 — 18,575 — Derivatives - interest rate swaps 555 — 555 — Derivatives - risk participation agreements 1 — 1 — Derivatives - customer foreign exchange forward 2 — 2 — Other investments 7,062 7,062 — — Liabilities: Derivatives - interest rate customer swaps $ 18,953 $ — $ 18,953 $ — Derivatives - interest rate swaps 80 — 80 — Derivatives - risk participation agreements 108 — 108 — Derivatives - customer foreign exchange forward 2 — 2 — Other liabilities 7,062 7,062 — — As of December 31, 2016 Fair value measurements at reporting date using: Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) (In thousands) Assets: Available-for-sale securities: U.S. government and agencies $ 39,936 $ 39,293 $ 643 $ — Government-sponsored entities 336,664 — 336,664 — Municipal bonds 293,397 — 293,397 — Mortgage-backed securities 570,327 — 570,327 — Other 23,808 23,808 — — Total available-for-sale securities 1,264,132 63,101 1,201,031 — Derivatives - interest rate customer swaps 17,032 — 17,032 — Derivatives - risk participation agreements 15 — 15 — Other investments 6,110 6,110 — — Liabilities: Derivatives - interest rate customer swaps $ 16,560 $ — $ 16,560 $ — Derivatives - interest rate swaps 1,040 — 1,040 — Derivatives - risk participation agreements 6 — 6 — Other liabilities 6,110 6,110 — — As of December 31, 2017 and 2016, available-for-sale securities consisted primarily of U.S. government and agency securities, government-sponsored entities securities, municipal bonds, mortgage-backed securities, and other available-for-sale securities. Available-for-sale Level 1 securities are valued with prices quoted in active markets and include U.S. Treasury securities (which are categorized as U.S. government and agencies securities) and equities (which are categorized as other available-for-sale securities). Available-for-sale Level 2 securities generally have quoted prices but are traded less frequently than exchange-traded securities and can be priced using market data from similar assets and include government-sponsored entities securities, municipal bonds, mortgage-backed securities, and certain investments in SBA loans (which are categorized as U.S. government and agencies securities). No investments held at December 31, 2017 or 2016 were categorized as Level 3. There were no changes in the valuation techniques used for measuring the fair value, nor were there any transfers between Levels 1 and 2, of available-for-sale securities in the years ended December 31, 2017 and 2016. In managing its interest rate and credit risk, the Company utilizes derivative instruments including interest rate customer swaps, interest rate swaps, and risk participation agreements. As a service to its customers. the Company may utilize derivative instruments including customer foreign exchange forward contracts to manage its foreign exchange risk, if any. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities, and therefore, they have been categorized as a Level 2 measurement as of December 31, 2017 and 2016 . There were no transfers between Levels 1 and 2 in the years ended 2017 and 2016. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 9: Derivatives and Hedging Activities” for further details. To comply with the provisions of ASC 820, the Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts and guarantees. Counterparty exposure is evaluated by netting positions that are subject to master netting agreements, as well as considering the amount of collateral securing the position. The Company has determined that the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, although the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by itself and its counterparties. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy as of December 31, 2017 and 2016 . Other investments, which are not considered available-for-sale investments, consist of deferred compensation trusts, which consist of publicly traded mutual fund investments that are valued at prices quoted in active markets. Therefore, they have been categorized as a Level 1 measurement as of December 31, 2017 and 2016 . There were no transfers between Levels 1 and 2 in the years ended 2017 and 2016. There were no Level 3 assets valued on a recurring basis as of December 31, 2017 or 2016 . The following tables present the Company’s assets and liabilities measured at fair value on a non-recurring basis during the periods ended December 31, 2017 and 2016 , respectively, aggregated by the level in the fair value hierarchy within which those measurements fall: As of December 31, 2017 Fair value measurements at reporting date using: Gain (losses) from fair value changes Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Year ended December 31, 2017 (In thousands) Assets: Impaired loans (1) $ 1,778 $ — $ — $ 1,778 $ (465 ) Goodwill (2) 42,054 — — 42,054 (24,901 ) $ 43,832 $ — $ — $ 43,832 $ (25,366 ) ___________________ (1) Collateral-dependent impaired loans held as of December 31, 2017 that had write-downs in fair value or whose specific reserve changed during 2017. (2) Goodwill balance at Anchor as of December 31, 2017 that had write-downs in fair value during 2017. The goodwill balance related to Anchor is recorded in other assets held for sale as of December 31, 2017 . See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for further detail. As of December 31, 2016 Fair value measurements at reporting date using: Gain (losses) from fair value changes Quoted prices in Significant Significant Year ended December 31, 2016 (In thousands) Assets: Impaired loans (1) $ 3,074 $ — $ — $ 3,074 $ (428 ) OREO (2) 1,690 — — 1,690 (110 ) Goodwill (3) 34,777 — — 34,777 (9,528 ) $ 39,541 $ — $ — $ 39,541 $ (10,066 ) ___________________ (1) Collateral-dependent impaired loans held as of December 31, 2016 that had write-downs in fair value or whose specific reserve changed during 2016 (2) OREO held as of December 31, 2016 that had write-downs in fair value during 2016. (3) Goodwill balance at Boston Private Wealth as of December 31, 2016 that had write-downs in fair value during 2016. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for further detail. The following tables present additional quantitative information about assets measured at fair value on a non-recurring basis for which the Company has utilized Level 3 inputs to determine fair value: As of December 31, 2017 Fair Valuation Unobservable Range of Weighted (In thousands) Impaired Loans $ 1,778 Appraisals of Collateral Discount for costs to sell 0% - 7% 5% Appraisal adjustments 0% - 20% 14% See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for additional quantitative information about the 2017 goodwill impairment charges at Anchor. As of December 31, 2016 Fair Valuation Unobservable Range of Weighted (In thousands) Impaired Loans $ 3,074 Appraisals of Collateral Discount for costs to sell 5% - 7% 6% Appraisal adjustments 0% - 20% 13% OREO $ 1,690 Appraisals of Collateral Discount for costs to sell 6% 6% Appraisal adjustments 18% 18% See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for additional quantitative information about the 2016 goodwill impairment charges at Boston Private Wealth. Impaired loans include those loans that were adjusted to the fair value of underlying collateral as required under ASC 310, Receivables . The amount does not include impaired loans that are measured based on expected future cash flows discounted at the respective loan’s original effective interest rate, as that amount is not considered a fair value measurement. The Company uses appraisals, which management may adjust to reflect estimated fair value declines, or apply other discounts to appraised values for unobservable factors resulting from its knowledge of the property or consideration of broker quotes. The appraisers use a market, income, and/or a cost approach in determining the value of the collateral. Therefore they have been categorized as a Level 3 measurement. The following tables present the carrying values and fair values of the Company’s financial instruments that are not measured at fair value on a recurring basis (other than certain loans, as noted below): As of December 31, 2017 Book Value Fair Value Quoted prices Significant Significant (In thousands) FINANCIAL ASSETS: Cash and cash equivalents $ 120,541 $ 120,541 $ 120,541 $ — $ — Investment securities held-to-maturity 74,576 73,781 — 73,781 — Loans held for sale 4,697 4,737 — 4,737 — Loans, net 6,430,286 6,388,297 — — 6,388,297 Other financial assets 93,449 93,449 — 93,449 — FINANCIAL LIABILITIES: Deposits 6,510,246 6,509,197 — 6,509,197 — Securities sold under agreements to repurchase 32,169 32,169 — 32,169 — Federal funds purchased 30,000 30,000 — 30,000 — Federal Home Loan Bank borrowings 693,681 692,402 — 692,402 — Junior subordinated debentures 106,363 96,363 — — 96,363 Other financial liabilities 2,224 2,224 — 2,224 — As of December 31, 2016 Book Value Fair Value Quoted prices Significant Significant (In thousands) FINANCIAL ASSETS: Cash and cash equivalents $ 106,557 $ 106,557 $ 106,557 $ — $ — Investment securities held-to-maturity 93,079 92,604 — 92,604 — Loans held for sale 3,464 3,428 — 3,428 — Loans, net 6,036,277 6,021,611 — — 6,021,611 Other financial assets 77,956 77,956 — 77,956 — FINANCIAL LIABILITIES: Deposits 6,085,146 6,084,765 — 6,084,765 — Securities sold under agreements to repurchase 59,624 59,624 — 59,624 — Federal funds purchased 80,000 80,000 — 80,000 — Federal Home Loan Bank borrowings 734,205 734,941 — 734,941 — Junior subordinated debentures 106,363 96,363 — — 96,363 Other financial liabilities 1,942 1,942 — 1,942 — The estimated fair values have been determined by using available quoted market information or other appropriate valuation methodologies. The aggregate fair value amounts presented above do not represent the underlying value of the financial assets and liabilities of the Company taken as a whole as they do not reflect any premium or discount the Company might recognize if the assets were sold or the liabilities sold, settled, or redeemed. An excess of fair value over book value on financial assets represents a premium, or gain, the Company might recognize if the assets were sold, while an excess of book value over fair value on financial liabilities represents a premium, or gain, the Company might recognize if the liabilities were sold, settled, or redeemed prior to maturity. Conversely, losses would be recognized if assets were sold where the book value exceeded the fair value or liabilities were sold where the fair value exceeded the book value. The fair value estimates provided are made at a specific point in time, based on relevant market information and the characteristics of the financial instrument. The estimates do not provide for any premiums or discounts that could result from concentrations of ownership of a financial instrument. Because no active market exists for some of the Company’s financial instruments, certain fair value estimates are based on subjective judgments regarding current economic conditions, risk characteristics of the financial instruments, future expected loss experience, prepayment assumptions, and other factors. The resulting estimates involve uncertainties and are considered best estimates. Changes made to any of the underlying assumptions could significantly affect the estimates. Cash and cash equivalents The carrying value reported in the balance sheet for cash and cash equivalents approximates fair value due to the short-term nature of their maturities and are classified as Level 1. Held-to-maturity investment securities Held-to-maturity securities currently include mortgage-backed securities. The mortgage-backed securities are fixed income instruments that are not quoted on an exchange, but may be traded in active markets. The fair value of these securities is based on quoted market prices obtained from external pricing services. The principal market for our securities portfolio is the secondary institutional market, with an exit price that is predominantly reflective of bid level pricing in that market. Accordingly, held-to-maturity mortgage-backed securities are included in the Level 2 fair value category. Loans held for sale Loans held for sale are recorded at the lower of cost or fair value in the aggregate. Fair value estimates are based on actual commitments to sell the loans to investors at an agreed upon price or current market prices if rates have changed since the time the loan closed. Accordingly, loans held for sale are included in the Level 2 fair value category. Loans, net Fair value estimates are based on loans with similar financial characteristics. Fair values of commercial and residential mortgage loans are estimated by discounting contractual cash flows adjusted for prepayment estimates and using discount rates approximately equal to current market rates on loans with similar credit and interest rate characteristics and maturities. The fair value estimates for home equity and other loans are based on outstanding loan terms and pricing in the local markets. The method of estimating the fair value of the loans disclosed in the table above does not incorporate the exit price concept in the presentation of the fair value of these financial instruments. Net loans are included in the Level 3 fair value category based upon the inputs and valuation techniques used. Other financial assets Other financial assets consist of accrued interest and fees receivable, and stock in Federal Home Loan Bank (“FHLB”) and the Federal Reserve Bank (“FRB”), for which the carrying amount approximates fair value, and are classified as Level 2. Deposits The fair values reported for transaction accounts (demand, NOW, savings, and money market) equal their respective book values reported on the balance sheet and are classified as Level 2. The fair values disclosed are, by definition, equal to the amount payable on demand at the reporting date. The fair values for certificates of deposit are based on the discounted value of contractual cash flows. The discount rates used are representative of approximate rates currently offered on certificates of deposit with similar remaining maturities and are classified as Level 2. Securities sold under agreements to repurchase The fair value of securities sold under agreements to repurchase are estimated based on contractual cash flows discounted at the Bank’s incremental borrowing rate for FHLB borrowings with similar maturities and have been classified as Level 2. Federal funds purchased The carrying amounts of federal funds purchased approximate fair value due to their short-term nature and therefore these funds have been classified as Level 2. Federal Home Loan Bank borrowings The fair value reported for FHLB borrowings is estimated based on the discounted value of contractual cash flows. The discount rate used is based on the Bank’s estimated current incremental borrowing rate for FHLB borrowings of similar maturities and therefore these borrowings have been classified as Level 2. Junior subordinated debentures The fair value of the junior subordinated debentures issued by Boston Private Capital Trust I and Boston Private Capital Trust II were estimated using Level 3 inputs such as the interest rates on these securities, current rates for similar debt, a consideration for illiquidity of trading in the debt, and regulatory changes that would result in an unfavorable change in the regulatory capital treatment of this type of debt. Other financial liabilities Other financial liabilities consists of accrued interest payable for which the carrying amount approximates fair value and is classified as Level 2. Financial instruments with off-balance sheet risk The Bank’s commitments to originate loans and for unused lines and outstanding letters of credit are primarily at market interest rates and therefore, the carrying amount approximates fair value.

Financial Instruments With Off-

Financial Instruments With Off-Balance Sheet Risk	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments Disclosure [Text Block]	FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK The Company is party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its clients. These financial instruments include commitments to originate loans, unadvanced portion of loans, unused lines of credit, standby letters of credit, commitments to sell loans, and rate locks related to loans that if originated will be held for sale. The instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheets. The contract or notional amounts of those instruments reflect the extent of involvement the Company has in particular classes of financial instruments. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for loan commitments and standby letters of credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. Commitments to originate loans, the unadvanced portion of loans, and the unused lines of credit are agreements to lend to a client, provided there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since certain commitments may expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each client’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the borrower. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance by a client to a third party. The credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan facilities to clients. Loans sold to investors have recourse to the Company on any loans that are deemed to have been fraudulent or misrepresented. In addition, investors would require the Company to repurchase any loan sold which has a first payment default. The Company has not repurchased any loans during the years ended December 31, 2017 and 2016. Financial instruments with off-balance sheet risk are summarized as follows: December 31, 2017 2016 (In thousands) Commitments to originate loans Variable rate $ 56,410 $ 103,189 Fixed rate 79,784 65,563 Total commitments to originate new loans $ 136,194 $ 168,752 Unadvanced portion of loans and unused lines of credit $ 1,327,140 $ 1,280,648 Standby letters of credit $ 46,291 $ 38,391 Forward commitments to sell loans $ 16,886 $ 9,663

Boston Private Financial Holdin

Boston Private Financial Holdings, Inc. (Parent Company Only)	12 Months Ended
	Dec. 31, 2017
BOSTON PRIVATE FINANCIAL HOLDINGS, INC. (PARENT COMPANY ONLY) [Abstract]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	BOSTON PRIVATE FINANCIAL HOLDINGS, INC. (PARENT COMPANY ONLY) CONDENSED BALANCE SHEETS December 31, 2017 December 31, 2016 (In thousands) Assets: Cash and cash equivalents $ 66,361 $ 54,694 Investment in wholly-owned and majority-owned subsidiaries: Bank 731,907 694,517 Non-banks 110,764 137,262 Investment in partnerships and trusts 6,340 6,340 Other assets 11,046 17,131 Total assets $ 926,418 $ 909,944 Liabilities: Junior subordinated debentures $ 106,363 $ 106,363 Deferred income taxes 5,322 8,638 Other liabilities 11,328 9,490 Total liabilities 123,013 124,491 Redeemable Noncontrolling Interests (1) 22,647 21,133 Total Shareholders’ Equity 780,758 764,320 Total liabilities, redeemable noncontrolling interests and shareholders’ equity $ 926,418 $ 909,944 ___________________ (1) Includes noncontrolling interests and the maximum redemption value of redeemable noncontrolling interests. CONDENSED STATEMENTS OF OPERATIONS Year ended December 31, 2017 2016 2015 (In thousands) Income: Interest income $ 180 $ 130 $ 116 Dividends from subsidiaries: Bank 25,200 22,700 22,700 Non-banks 24,116 24,044 28,789 Other income (1,071 ) 310 236 Total income 48,425 47,184 51,841 Operating Expense: Salaries and employee benefits 4,061 4,620 10,320 Professional fees 1,369 1,337 2,007 Interest expense 2,919 2,427 3,875 Other expenses 1,424 1,381 2,740 Total operating expense 9,773 9,765 18,942 Income before income taxes 38,652 37,419 32,899 Income tax benefit (6,880 ) (3,751 ) (6,877 ) Net income from discontinued operations 4,870 5,541 6,411 Income before equity in undistributed earnings of subsidiaries 50,402 46,711 46,187 Equity / (loss) in undistributed earnings of subsidiaries (9,811 ) 24,917 18,738 Net income attributable to the Company $ 40,591 $ 71,628 $ 64,925 CONDENSED STATEMENTS OF CASH FLOWS Year ended December 31, 2017 2016 2015 (In thousands) Cash flows from operating activities: Net income attributable to the Company $ 40,591 $ 71,628 $ 64,925 Net income from discontinued operations 4,870 5,541 6,411 Net income from continuing operations 35,721 66,087 58,514 Adjustments to reconcile net income from continuing operations to net cash provided by/ (used in) operating activities: Equity in earnings/ (loss) of subsidiaries: Bank (50,476 ) (58,184 ) (57,201 ) Non-banks 11,150 (13,477 ) (13,026 ) Dividends from subsidiaries: Bank 25,200 22,700 22,700 Non-banks 24,116 24,044 28,789 Deferred income tax expense/ (benefit) (3,075 ) 10,000 (4,575 ) Depreciation and amortization 3,553 (738 ) 5,097 Net decrease/ (increase) in other operating activities 1,899 (16,633 ) 2,167 Net cash provided by/ (used in) operating activities of continuing operations 48,088 33,799 42,465 Net cash provided by/ (used in) operating activities of discontinued operations 4,870 5,541 6,411 Net cash provided by/ (used in) operating activities 52,958 39,340 48,876 Cash flows from investing activities: Cash paid for acquisitions, including deferred acquisition obligations 1,410 1,890 1,821 Capital investments in subsidiaries: Bank — — — Non-banks (54 ) (1,220 ) (1,723 ) Net cash (used in)/ provided by in other investing activities — 1 1 Net cash provided by/ (used in) investing activities 1,356 671 99 Cash flows from financing activities: Repurchase of common stock — (9,323 ) — Dividends paid to common shareholders (37,054 ) (33,110 ) (29,608 ) Dividends paid to preferred shareholders (3,475 ) (3,475 ) (3,475 ) Tax benefit/ (deficiency) from certain stock compensation awards — (620 ) (1,262 ) Proceeds from stock option exercises 882 1,725 1,206 Proceeds from issuance of common stock, net 2,740 7,786 160 Other equity adjustments (5,740 ) (3,685 ) (5,204 ) Net cash provided by/ (used in) financing activities (42,647 ) (40,702 ) (38,183 ) Net (decrease)/ increase in cash and cash equivalents 11,667 (691 ) 10,792 Cash and cash equivalents at beginning of year 54,694 55,385 44,593 Cash and cash equivalents at end of year $ 66,361 $ 54,694 $ 55,385

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2017
REGULATORY MATTERS [Abstract]
Regulatory Capital Requirements under Banking Regulations [Text Block]	REGULATORY MATTERS Wealth Management and Trust, Investment Management, and Wealth Advisory The Company’s Wealth Management and Trust, Investment Management, and Wealth Advisory businesses are highly regulated, primarily at the federal level by the SEC, and by state regulatory agencies. The Company has subsidiaries which are RIAs under the Investment Advisers Act of 1940. The Investment Advisers Act of 1940 imposes numerous obligations on RIAs, including fiduciary, record keeping, operational, and disclosure obligations. The subsidiaries, as investment advisers, are also subject to regulation under the federal and state securities laws and the fiduciary laws of certain states. In addition, the Company has subsidiaries which act as sub-advisers to mutual funds, which are registered under the Investment Company Act of 1940 and are subject to that Act’s provisions and regulations. The Company’s subsidiaries are also subject to the provisions and regulations of ERISA, to the extent any such entities act as a “fiduciary” under ERISA with respect to certain of its clients. ERISA and the related provisions of the federal tax laws impose a number of duties on persons who are fiduciaries under ERISA, and prohibit certain transactions involving the assets of each ERISA plan which is a client, as well as certain transactions by the fiduciaries and certain other related parties to such plans. Private Banking The Company and the Bank are subject to extensive supervision and regulation by the Federal Reserve, the FDIC, which insures the deposits of the Bank to the maximum extent permitted by law, and the Massachusetts Commissioner of Banks. The federal and state laws and regulations which are applicable to banks regulate, among other things, the scope of their business, their investments, their reserves against deposits, the timing of the availability of deposited funds, and the nature and amount of collateral for certain loans. The laws and regulations governing the Bank generally have been promulgated to foster the safety and soundness of the Bank and protect depositors, and not for the purpose of protecting shareholders of the Company. As of December 31, 2017, quantitative measures established by regulation to ensure capital adequacy required us to maintain minimum ratios of CET1, Tier 1, and total capital (as defined in the regulations) to risk-weighted assets (as defined in the regulations) and of Tier 1 capital (as defined in the regulations) to average assets (as defined in the regulations). The following table presents the Company’s and the Bank’s amount of regulatory capital and related ratios as of December 31, 2017 and 2016 . Also presented are the minimum requirements established by the Federal Reserve and the FDIC as of those dates for the Company and the Bank, respectively, to meet applicable capital requirements and the requirements of the FDIC as of those dates for the Bank to be considered “well capitalized” under the FDIC’s prompt corrective action provisions. On July 28, 2017, Boston Private Bank became a member of the Federal Reserve System. The Federal Reserve and the Massachusetts Commissioner of Banks may impose higher capital ratios than those listed below based upon the results of regulatory exams. The Bank was categorized as “well capitalized” under the FDIC’s prompt corrective action provisions as of December 31, 2017 and 2016 . Actual For capital adequacy purposes (at least) To be well capitalized under prompt corrective action provisions (at least) Basel III minimum capital ratio with capital conservation buffer (1) Amount Ratio Amount Ratio Amount Ratio (In thousands) As of December 31, 2017 Common equity tier 1 risk-based capital Company $ 607,800 10.32 % $ 265,153 4.5 % n/a n/a 7.0 % Boston Private Bank 694,201 11.83 264,028 4.5 $ 381,373 6.5 % 7.0 Tier 1 risk-based capital Company 758,089 12.87 353,537 6.0 n/a n/a 8.5 Boston Private Bank 694,201 11.83 352,037 6.0 469,382 8.0 8.5 Total risk-based capital Company 832,182 14.12 471,383 8.0 n/a n/a 10.5 Boston Private Bank 767,576 13.08 469,382 8.0 586,728 10.0 10.5 Tier 1 leverage capital Company 758,089 9.34 324,725 4.0 n/a n/a 4.0 Boston Private Bank 694,201 8.63 321,920 4.0 402,400 5.0 4.0 As of December 31, 2016 Common equity tier 1 risk-based capital Company $ 571,663 10.00 % $ 257,222 4.5 % n/a n/a 7.0 % Boston Private Bank 661,991 11.64 256,030 4.5 $ 369,822 6.5% 7.0 Tier 1 risk-based capital Company 722,674 12.64 342,962 6.0 n/a n/a 8.5 Boston Private Bank 661,991 11.64 341,374 6.0 455,165 8.0 8.5 Total risk-based capital Company 794,584 13.90 457,283 8.0 n/a n/a 10.5 Boston Private Bank 733,214 12.89 455,165 8.0 568,956 10.0 10.5 Tier 1 leverage capital Company 722,674 9.42 306,848 4.0 n/a n/a 4.0 Boston Private Bank 661,991 8.70 304,510 4.0 380,637 5.0 4.0 ___________________ n/a = not applicable (1) Required capital ratios under the Basel III capital rules with the fully phased-in capital conservation buffer added to the minimum risk-based capital ratios. The fully phased-in ratios are effective for 2019, with lower requirements during the transition years 2016 through 2018. Bank regulatory authorities restrict the Bank from lending or advancing funds to, or investing in the securities, of the Company. Further, these authorities restrict the amounts available for the payment of dividends by the Bank to the Company. The Company has sponsored the creation of two statutory trusts for the sole purpose of issuing trust preferred securities and investing the proceeds in junior subordinated debentures of the Company. In accordance with ASC 810-10-55, Consolidation - Overall - Implementation Guidance and Illustrations - Variable Interest Entities , these statutory trusts created by the Company are not consolidated into the Company’s financial statements; however, the Company reflects the amounts of junior subordinated debentures payable to the preferred stockholders of statutory trusts as debt in its financial statements. As of both December 31, 2017 , and 2016 , all $100.0 million of the net balance of these trust preferred securities qualified as Tier 1 capital.

Litigation and Contingencies

Litigation and Contingencies	12 Months Ended
	Dec. 31, 2017
LITIGATION AND CONTINGENCIES [Abstract]
Legal Matters and Contingencies [Text Block]	LITIGATION AND CONTINGENCIES The Company is involved in routine legal proceedings occurring in the ordinary course of business. In the opinion of management, final disposition of these proceedings will not have a material adverse effect on the consolidated balance sheets, consolidated statements of operations, or consolidated statements of cash flows of the Company.

Selected Quarterly Data (Unaudi

Selected Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
SELECTED QUARTERLY DATA (UNAUDITED) [Abstract]
Quarterly Financial Information [Text Block]	SELECTED QUARTERLY DATA (UNAUDITED) The following tables present selected quarterly financial data for 2017 and 2016 : 2017 (1) (In thousands, except per share data) Fourth Quarter Third Quarter Second Quarter First Quarter Revenues Net interest income $ 57,272 $ 56,627 $ 57,145 $ 53,642 Fees and other income 39,175 40,267 38,018 36,506 Total revenues 96,447 96,894 95,163 90,148 Provision/ (credit) for loan losses (942 ) (432 ) (6,114 ) (181 ) Operating expense 93,989 69,346 67,821 68,780 Income before income taxes 3,400 27,980 33,456 21,549 Income tax expense 21,391 8,289 9,963 6,553 Net income from discontinued operations 989 1,186 1,063 1,632 Less: Net income attributable to noncontrolling interests 1,278 1,074 1,150 966 Net income/ (loss) attributable to the Company $ (18,280 ) $ 19,803 $ 23,406 $ 15,662 Net earnings/ (loss) per share attributable to the Company’s common shareholders: Basic earnings/ (loss) per share (2) $ (0.24 ) $ 0.23 $ 0.28 $ 0.18 Diluted earnings/ (loss) per share (2) $ (0.24 ) $ 0.22 $ 0.27 $ 0.17 2016 (1) (In thousands, except per share data) Fourth Quarter Third Quarter Second Quarter First Quarter Revenues Net interest income $ 51,519 $ 49,871 $ 49,169 $ 49,879 Fees and other income 43,958 40,012 36,795 38,022 Total revenues 95,477 89,883 85,964 87,901 Provision/ (credit) for loan losses (1,128 ) (138 ) (2,535 ) (3,133 ) Operating expense 71,843 61,670 64,731 66,709 Income before income taxes 24,762 28,351 23,768 24,325 Income tax expense 7,247 8,652 7,626 7,438 Net income from discontinued operations 1,184 1,047 1,245 2,065 Less: Net income attributable to noncontrolling interests 1,147 1,110 989 911 Net income attributable to the Company $ 17,552 $ 19,636 $ 16,398 $ 18,041 Net earnings per share attributable to the Company’s common shareholders: Basic earnings per share (2) $ 0.19 $ 0.23 $ 0.19 $ 0.22 Diluted earnings per share (2) $ 0.19 $ 0.22 $ 0.18 $ 0.21 ___________________ (1) Due to rounding, the sum of the four quarters may not add to the year to date total. (2) Includes the effect of adjustments to net income attributable to the Company to arrive at net income attributable to common shareholders.

Basis of Presentation and Sum35

Basis of Presentation and Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Basis of Presentation and Significant Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Boston Private Financial Holdings, Inc. (the “Company” or “BPFH”), is a bank holding company (the “Holding Company”) with four reportable segments: Private Banking, Wealth Management and Trust, Investment Management, and Wealth Advisory. The Private Banking segment is comprised of the banking operations of Boston Private Bank & Trust Company (the “Bank” or “Boston Private Bank”), a trust company chartered by The Commonwealth of Massachusetts, insured by the Federal Deposit Insurance Corporation (the “FDIC”), and a wholly-owned subsidiary of the Company. Boston Private Bank is a member of the Federal Reserve Bank of Boston. Boston Private Bank currently operates in three geographic markets: New England, the San Francisco Bay Area, and Southern California. The Wealth Management and Trust segment is comprised of the operations of Boston Private Wealth LLC (“Boston Private Wealth”), a wholly-owned subsidiary of Boston Private Bank, and the trust operations of Boston Private Bank. The segment offers investment management, wealth management, family office, and trust services to individuals, families, and institutions. The Wealth Management and Trust segment operates in New England; South Florida; California; and Madison, Wisconsin. The Investment Management segment currently has two consolidated affiliates, Dalton, Greiner, Hartman, Maher & Co., LLC (“DGHM”) and Anchor Capital Advisors, LLC (“Anchor”) (together, the “Investment Managers”). In December 2017, the Company entered into an agreement to sell its entire ownership interest in Anchor in a transaction that will result in Anchor being majority-owned by members of its management team. The transaction is expected to close in the first quarter of 2018. This transaction has been approved by the Company’s board of directors and is subject to obtaining client consents, Anchor raising debt financing, and customary closing conditions. The Wealth Advisory segment has two consolidated affiliates, KLS Professional Advisors Group, LLC (“KLS”) and Bingham, Osborn & Scarborough, LLC (“BOS”) (together, the “Wealth Advisors” and, together with the Wealth Management and Trust and Investment Management segments, the “Wealth and Investment” businesses). Basis of Presentation The consolidated financial statements of the Company include the accounts of the Company and its wholly-owned and majority-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation, and the portion of income allocated to owners other than the Company is included in “Net income attributable to noncontrolling interests” in the consolidated statements of operations. Redeemable noncontrolling interests in the consolidated balance sheets reflect the maximum redemption value of agreements with other owners. All accounts related to divested affiliates are included within the results of discontinued operations for all periods presented. The financial statements are prepared in accordance with accounting principles generally accepted in the United States (“U.S.”) (“GAAP”). Reclassifications of amounts in prior years’ consolidated financial statements are made whenever necessary to conform to the current year’s presentation.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates In preparing the consolidated financial statements, management is required to make certain estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and revenues and expenses for the period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to change, in the near term, relate to the determination of the allowance for loan losses, evaluation of potential impairment of goodwill and other intangibles, and income tax estimates.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Significant Group Concentrations of Credit Risk Most of the Company’s activities are with clients within the New England, the San Francisco Bay Area, and Southern California regions of the country. The Company does not believe it has any significant concentrations in any one industry, geographic location, or with any one client. Part II. Item 8. “Financial Statements and Supplementary Data - Note 4: Investment Securities,” highlights the types of securities in which the Company invests, and Part II. Item 8. “Financial Statements and Supplementary Data - Note 5: Loan Portfolio and Credit Quality,” describes the concentration of the Private Banking loan data based on the location of the lender.
Cash and Cash Equivalents, Policy [Policy Text Block]	Statement of Cash Flows For purposes of reporting cash flows, the Company considers cash and due from banks which have original maturities with 90 days or less to be cash equivalents.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Due from Banks The Bank is required to maintain average reserve balances in an account with the Federal Reserve based upon a percentage of certain deposits. As of December 31, 2017 and 2016 , the daily amounts required to be held in the aggregate for the Bank were $3.6 million and $5.0 million , respectively.
Marketable Securities, Policy [Policy Text Block]	Investment Securities Available-for-sale investment securities are reported at fair value, with unrealized gains and losses credited or charged, net of the estimated tax effect, to accumulated other comprehensive income/ (loss). Held-to-maturity investment securities are those which the Company has the positive intent and ability to hold to maturity and are reported at amortized cost. Premiums and discounts on the investment securities are amortized or accreted into net interest income by the level-yield method. Gains and losses on the sale of the available-for-sale investments are recognized at the trade date on a specific identification basis. Dividend and interest income is recognized when earned and is recorded on the accrual basis. The Company conducts a quarterly review and evaluation of its investment securities to determine if the decline in fair value of a security below its amortized cost is deemed to be other-than-temporary. Other-than-temporary impairment losses are recognized on securities when: (i) the holder has an intention to sell the security; (ii) it is more likely than not that the security will be required to be sold prior to recovery; or (iii) the holder does not expect to recover the entire amortized cost basis of the security. Other-than-temporary losses are reflected in earnings as a charge against gain on sale of investments, net, to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in accumulated other comprehensive income/ (loss). The Company has no intention to sell any securities in an unrealized loss position at December 31, 2017 nor is it more likely than not that the Company would be required to sell such securities prior to the recovery of the unrealized losses. As of December 31, 2017 , the Company believes that all impairments of investment securities are temporary in nature. No other-than-temporary impairment losses were recognized in the consolidated statements of operations for the years ended December 31, 2017 , 2016 , and 2015 .
Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block]	Loans Held for Sale Loans originated and held for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Fair value is based on commitments on hand from investors or prevailing market prices. Unrealized losses, if any, are recognized through a valuation allowance by charges to income. Loans transferred to the held for sale category from the loan portfolio are transferred at the lower of cost or fair value, usually as determined at the individual loan level. If fair value is less than cost, then a charge for the difference will be made to the allowance for loan losses if the decline in value is due to credit issues. Gains or losses on the sale of loans are recognized at the time of sale on a specific identification basis. Interest income is recognized on an accrual basis when earned.
Finance, Loans and Leases Receivable, Policy [Policy Text Block]	Loans Loans are carried at the principal amount outstanding, net of participations, deferred loan origination fees and costs, charge-offs, and interest payments applied to principal on nonaccrual loans. Loan origination fees, net of related direct incremental loan origination costs, are deferred and recognized into income over the contractual lives of the related loans as an adjustment to the loan yield, using the level-yield method. If a loan is paid off prior to maturity, the unamortized portion of net fees/cost is recognized into interest income. If a loan is sold, the unamortized portion of net fees/cost is recognized at the time of sale as a component of the gain or loss on sale of loans. When the Company analyzes its loan portfolio to determine the adequacy of its allowance for loan losses, it categorizes the loans by portfolio segment and class of financing receivable based on the similarities in risk characteristics for the loans. The Company has determined that its portfolio segments and classes of financing receivables are one and the same, with the exception of the commercial and industrial portfolio segment, which consists of other commercial and industrial loans and commercial tax-exempt loans. The level at which the Company develops and documents its allowance for loan loss methodology is consistent with the grouping of financing receivables based upon initial measurement attributes, risk characteristics, and the Company’s method for monitoring and assessing credit risks. These portfolio segments and classes of financing receivables are: • Commercial and industrial (portfolio segment) ◦ Other commercial and industrial loans (class of financing receivable) - Commercial and industrial loans include working capital and revolving lines of credit, term loans for equipment and fixed assets, and Small Business Administration (“SBA”) loans. ◦ Commercial tax-exempt loans (class of financing receivable) - Commercial tax-exempt loans include loans to not-for-profit private schools, colleges, and public charter schools. • Commercial real estate (segment and class) - Commercial real estate loans are generally acquisition financing for commercial properties such as office buildings, retail properties, apartment buildings, and industrial/warehouse space. In addition, tax-exempt commercial real estate loans are provided for affordable housing development and rehabilitation. These loans are often supplemented with federal, state, and/or local subsidies. • Construction and land (segment and class) - Construction and land loans include loans for financing of new developments as well as financing for improvements to existing buildings. In addition, tax-exempt construction and land loans are provided for the construction phase of the commercial tax-exempt and commercial real estate tax-exempt loans described above. • Residential mortgage (segment and class) - Residential mortgage loans consist of loans secured by single-family and one- to four-unit properties in excess of the amount eligible for purchase by the Federal National Mortgage Association, which was $424 thousand at December 31, 2017 for the “General” limit and $636 thousand for single-family properties for the “High-Cost” limit, depending on which specific geographic region of the Bank’s primary market areas the loan was originated. While the Bank has no minimum size for mortgage loans, it concentrates its origination activities in the “Jumbo” segment of the market. • Home equity (segment and class) - Home equity loans consist of balances outstanding on second mortgages and home equity lines of credit extended to individual clients. Personal lines of credit are typically for high net worth clients whose assets may not be liquid due to investments or closely held stock. The amount of home equity loans typically depends on client demand. • Consumer and other (segment and class) - Consumer and other loans consist of balances outstanding on consumer loans including personal lines of credit, and loans arising from overdraft protection extended to individual and business clients. Personal lines of credit are typically for high net worth clients whose assets may not be liquid due to investments or closely held stock. The amount of consumer and other loans typically depends on client demand. The past due status of a loan is determined in accordance with its contractual repayment terms. All portfolio segments are reported past due when one scheduled payment is due and unpaid for 30 days or more. The Bank’s policy is to discontinue the accrual of interest on a loan when the collectability of principal or interest is in doubt. When management determines that it is probable that the Bank will not collect all principal and interest on a loan in accordance with the original loan terms, the loan is designated as impaired. Impaired loans are usually commercial loans or construction and land loans, for which it is probable that the Company will not collect all amounts due according to the contractual terms of the loan agreement, and all loans restructured in a troubled debt restructuring. Accrual of interest income is discontinued and all interest previously accrued but not collected is reversed against current period interest income when a loan is initially classified as nonaccrual. Generally, interest received on nonaccrual loans is applied against principal or, on a limited basis, reported as interest income on a cash basis, when according to management’s judgment, the collectability of principal is reasonably assured. The Bank’s general policy for returning a loan to accrual status requires the loan to be brought current, for the client to show a history of making timely payments (generally six consecutive months), and when the financial position of the borrower and other relevant factors indicate there is no longer doubt as to the collectability of the loan. The Bank’s loan commitments are generally short-term in nature with terms that are primarily variable. Given the limited interest rate exposure posed by the commitments, the Bank estimates the fair value of these commitments to be immaterial.
Loans and Leases Receivable, Valuation, Policy [Policy Text Block]	Credit Quality Indicators The Bank uses a risk rating system to monitor the credit quality of its loan portfolio. Loan classifications are assessments made by the Bank of the status of the loans based on the facts and circumstances known to the Bank, including management’s judgment, at the time of assessment. Some or all of these classifications may change in the future if there are unexpected changes in the financial condition of the borrower, including but not limited to, changes resulting from continuing deterioration in general economic conditions on a national basis or in the local markets in which the Bank operates adversely affecting, among other things, real estate values. Such conditions, as well as other factors which adversely affect borrowers’ ability to service or repay loans, typically result in changes in loan default and charge-off rates, and increased provisions for loan losses, which would adversely affect the Company’s financial performance and financial condition. These circumstances are not entirely foreseeable and, as a result, it may not be possible to accurately reflect them in the Company’s analysis of credit risk. Generally, only commercial loans, including commercial real estate, other commercial and industrial loans, commercial tax-exempt loans, and construction and land loans, are given a numerical grade. A summary of the rating system used by the Bank follows: Pass - All loans graded as pass are considered acceptable credit quality by the Bank and are grouped for purposes of calculating the allowance for loan losses. For residential, home equity, and consumer loans, the Bank classifies loans as pass unless there is known information such as delinquency or client requests for modifications which, due to financial difficulty, would then generally result in a risk rating such as special mention or more severe depending on the factors. Special Mention - Loans rated in this category are defined as having potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may, at some future date, result in the deterioration of the repayment prospects for the credit or the Bank’s credit position. These loans are currently protected but have the potential to deteriorate to a substandard rating. For commercial loans, the borrower’s financial performance may be inconsistent or below forecast, creating the possibility of liquidity problems and shrinking debt service coverage. In loans having this rating, the primary source of repayment is still good, but there is increasing reliance on collateral or guarantor support. Collectability of the loan is not yet in jeopardy. In particular, loans in this category are considered more variable than other categories, since they will typically migrate through categories more quickly. Substandard - Loans rated in this category are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. A substandard credit has a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected. Substandard loans may be either still accruing or nonaccruing depending upon the severity of the risk and other factors such as the value of the collateral, if any, and past due status. Doubtful - Loans rated in this category indicate that collection or liquidation in full on the basis of currently existing facts, conditions, and values, is highly questionable and improbable. Loans in this category are usually on nonaccrual and classified as impaired.
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	Restructured Loans When the Bank, for economic or legal reasons related to a borrower’s financial difficulties, grants a concession to a troubled borrower that it would not otherwise consider, the loan is classified as a restructured loan pursuant to Accounting Standards Codification (“ASC”) 470, Debt . The concession either stems from an agreement between the creditor and the Bank or is imposed by law or a court. The concessions may include: • Deferral of principal and/or interest payments • Lower interest rate as compared to a new loan with comparable risk and terms • Extension of the maturity date • Reduction in the principal balance owed All loans whose terms have been modified in a troubled debt restructuring, including commercial, residential, and consumer, are evaluated for impairment under ASC 310, Receivables . Generally, a nonaccrual loan that is restructured remains on nonaccrual status for a period of at least six months to demonstrate that the borrower can meet the restructured terms. However, performance prior to the restructuring, or significant events that coincide with the restructuring, are considered when assessing whether the borrower can meet the new terms and may result in the loan being returned to accrual status at the time of the restructuring or after a shorter performance period. If the borrower’s ability to meet the revised payment schedule is uncertain, the loan remains classified as a nonaccrual loan. A loan may be removed from a restructured classification after the next fiscal year end, if the restructured terms include a market interest rate and the borrower has demonstrated performance with the restructured terms.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for Loan and Lease Losses The allowance for loan losses (“allowance”) is an estimate of the inherent risk of loss in the loan portfolio as of the consolidated balance sheet dates. Management estimates the level of the allowance based on all relevant information available. Changes to the required level in the allowance result in either a provision for loan loss expense, if an increase is required, or a credit to the provision, if a decrease is required. Loan losses are charged to the allowance when available information confirms that specific loans, or portions thereof, are uncollectible. Recoveries on loans previously charged-off are credited to the allowance when received in cash. The Company’s allowance is accounted for in accordance with guidance issued by various regulatory agencies, including: the Federal Financial Institutions Examination Council Policy Statement on the Allowance for Loan and Lease Losses (December 2006); Securities and Exchange Commission (“SEC”) Staff Accounting Bulletin No. 102, Selected Loan Loss Methodology and Documentation Issues ; ASC 310; and ASC 450, Contingencies . The allowance consists of three primary components: general reserves on pass graded loans, allocated reserves on non-impaired special mention and substandard loans, and the specific reserves on impaired loans. The calculation of the allowance involves a high degree of management judgment and estimates designed to reflect the inherent risk of loss in the loan portfolio at the measurement date. General reserves are calculated for each loan pool consisting of pass graded loans segregated by portfolio segment, by applying estimated net loss percentages based upon the Bank’s actual historical net charge-offs and, adjusted as appropriate, on a consistent manner based upon consideration of qualitative factors to arrive at a total loss factor for each portfolio segment. The rationale for qualitative adjustments is to more accurately reflect the current inherent risk of loss in the respective portfolio segments than would be determined through the sole consideration of the Bank’s actual historical net charge-off rates. The numerical factors assigned to each qualitative factor are based upon observable data, if applicable, as well as management’s analysis and judgment. The qualitative factors considered by the Company include: • Volume and severity of past due, nonaccrual, and adversely graded loans, • Volume and terms of loans, • Concentrations of credit, • Management’s experience, as well as loan underwriting and loan review policy and procedures, • Economic and business conditions impacting the Bank’s loan portfolio, as well as consideration of collateral values, and • External factors, including consideration of loss factor trends, competition, and legal and regulatory requirements. The Bank makes a determination of the applicable loss rate for these factors based on relevant local market conditions, credit quality, and portfolio mix. Each quarter, management reviews the loss factors to determine if there have been any changes in its loan portfolio, market conditions, or other risk indicators which would result in a change to the current loss factor. Allocated reserves on non-impaired special mention and substandard loans reflect management’s assessment of increased risk of losses associated with these types of adversely graded loans. An allocated reserve is assigned to these pools of loans based upon management’s consideration of the credit attributes of individual loans within each pool of loans, including consideration of loan to value ratios, past due status, strength and willingness of the guarantors, and other relevant attributes, as well as the qualitative factors considered for the general reserve as discussed above. These considerations are determined separately for each type of portfolio segment. The allocated reserves are a multiple of the general reserve for each respective portfolio segments, with a greater multiple for loans with increased risk ( i.e. , special mention loans versus substandard loans). A loan is considered impaired in accordance with ASC 310 when, based upon current information and events, it is probable that a creditor will be unable to collect all amounts due according to the contractual terms of the loan agreement. Impairment is measured based on the fair value of the loan, expected future cash flows discounted at the loan’s effective interest rate, or as a practical expedient, impairment may be determined based upon the observable market price of the loan, or the fair value of the collateral, less estimated costs to sell, if the loan is “collateral dependent.” A loan is collateral dependent if repayment of the loan is expected to be provided solely by the underlying collateral or sale of the underlying collateral. For collateral dependent loans, appraisals are generally used to determine the fair value. When a collateral dependent loan becomes impaired, an updated appraisal of the collateral is obtained, if appropriate. Appraised values are generally discounted for factors such as the Bank’s intention to liquidate the property quickly in a foreclosure sale or the date when the appraisal was performed if the Bank believes that collateral values have declined since the date the appraisal was done. The Bank may use a broker opinion of value in addition to an appraisal to validate the appraised value. In certain instances, the Bank may consider broker opinions of value as well as other qualitative factors while an appraisal is being prepared. If the loan is deemed to be collateral dependent, generally the difference between the book balance (client balance less any prior charge-offs or client interest payments applied to principal) and the fair value of the collateral is taken as a partial charge-off through the allowance for loan losses in the current period. If the loan is not determined to be collateral dependent, then a specific allocation to the general reserve is established for the difference between the book balance of the loan and the expected future cash flows discounted at the loan’s effective interest rate. Charge-offs for loans not considered to be collateral dependent are made when it is determined a loss has been incurred. Impaired loans are removed from the general loan pools. There may be instances where the loan is considered impaired although based on the fair value of underlying collateral or the discounted expected future cash flows there is no impairment to be recognized. In addition, all loans which are classified as troubled debt restructurings (“TDRs”) are considered impaired. In addition to the three primary components of the allowance for loan losses discussed above (general reserve, allocated reserves on non-impaired special mention and substandard loans, and the specific reserves on impaired loans), the Bank may also maintain an insignificant amount of additional allowance for loan losses (the unallocated allowance for loan losses). The unallocated reserve reflects the fact that the allowance for loan losses is an estimate and contains a certain amount of imprecision risk. It represents risks identified by Management that are not already captured in the qualitative factors discussed above. The unallocated allowance for loan losses is not considered significant by the Company and will remain at zero unless additional risk is identified. While this evaluation process utilizes historical and other objective information, the classification of loans and the establishment of the allowance for loan losses rely to a great extent on the judgment and experience of management. While management evaluates currently available information in establishing the allowance for loan losses, future adjustments to the allowance may be necessary if economic conditions differ substantially from the assumptions used in making the evaluations. In addition, various regulatory agencies, as an integral part of their examination process, periodically review a financial institution’s allowance for loan losses as well as loan grades/classifications. Such agencies may require the financial institution to recognize additions to the allowance for loan losses or increases to adversely graded loans based on their judgments about information available to them at the time of their examination.
Reserve for Unfunded Loan Commitments [Policy Text Block]	Reserve for Unfunded Loan Commitments The Company maintains a reserve for unfunded loan commitments for such items as unused portion of lines of credit and unadvanced construction loans. The reserve is maintained at a level that reflects the risk in these various commitments. Management determines the reserve percentages on a quarterly basis based on a percentage of the current historical loss rates for these portfolios. Once a loan commitment is funded, the reserve for unfunded loan commitment is reversed and a corresponding allowance for loan loss reserve is established. This unfunded loan commitment reserve is included in other liabilities in the consolidated balance sheets. Net adjustments to the reserve for unfunded commitments are included in other operating expense in the consolidated statements of operations.
Loans and Leases Receivable, Real Estate Acquired Through Foreclosure, Policy [Policy Text Block]	Other Real Estate Owned (“OREO”) OREO is comprised of property acquired through foreclosure proceedings or acceptance of a deed-in-lieu of foreclosure in partial or total satisfaction of certain loans. Properties are recorded at the lower of the recorded investment in the loan at the time of acquisition or the fair value, as established by a current appraisal, comparable sales, and other estimates of value obtained principally from independent sources, less estimated costs to sell. Any decline in fair value compared to the carrying value of a property at the time of acquisition is charged against the allowance for loan losses. Any subsequent valuation adjustments to reflect declines in current fair value, as well as gains or losses on disposition are reported in gain/(loss) on OREO, net in the consolidated statements of operations. Expenses incurred for holding or maintaining OREO properties such as real estate taxes, utilities, and insurance are charged as incurred to other operating expenses in the consolidated statements of operations. Rental income earned, although generally minimal, is offset against other operating expenses.
Property, Plant and Equipment, Policy [Policy Text Block]	Premises and Equipment Premises and equipment consists of leasehold improvements, furniture, fixtures, equipment, art, buildings, and land. Equipment consists primarily of computer equipment. Premises and equipment are carried at cost, less accumulated depreciation and amortization. Also included in premises and equipment is technology initiatives in process. Depreciation and amortization are computed primarily by the straight-line method over the estimated useful lives of the assets, or the terms of the leases, if shorter, for leasehold improvements. The estimated useful lives for leasehold improvements and buildings are 5-15 years and 40 years, respectively. The estimated useful life for furniture and fixtures is 2-10 years and is 3-5 years for computer equipment. The costs of improvements that extend the life of an asset are capitalized, while the cost of repairs and maintenance are expensed as incurred. Neither land nor art is depreciated.
Goodwill and Intangible Assets, Policy [Policy Text Block]	Valuation of Goodwill/Intangible Assets and Analysis for Impairment The Company allocates the cost of an acquired entity to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Other intangible assets identified in acquisitions generally consist of advisory contracts, trade names, and non-compete agreements. The value attributed to advisory contracts is based on the time period over which they are expected to generate economic benefits. The advisory contracts are generally amortized over 8-15 years, depending on the contract. Trade names are not amortized. Long-lived intangible assets are subject to the impairment provisions of ASC 360-10, Property, Plant, and Equipment (“ASC 360”). Long-lived intangible assets are tested for recoverability by comparing the net carrying value of the asset or asset group to the undiscounted net cash flows to be generated from the use and eventual disposition of that asset (asset group) when events or changes in circumstances indicate that its carrying amount may not be recoverable. If the carrying amount of the asset exceeds its net undiscounted cash flows, then an impairment loss is recognized for the amount by which the carrying amount exceeds its fair value, determined based upon the discounted value of the expected cash flows generated by the asset. The intangible impairment test is performed at the reporting unit level, and each affiliate with goodwill and/or intangible assets is considered a reporting unit for goodwill and intangible impairment testing purposes. The excess of the purchase price for acquisitions over the fair value of the net assets acquired, including other intangible assets, is recorded as goodwill. Goodwill is not amortized but is tested for impairment at the reporting unit level, defined as the affiliate level, at least annually in the fourth quarter or more frequently when events or circumstances occur that indicate that it is more likely than not that an impairment has occurred, based on the guidance in ASC 350, Intangibles -Goodwill and Other (“ASC 350”), as updated by ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). Goodwill impairment exists when a reporting unit’s carrying value of goodwill exceeds its implied fair value. In accordance with ASC 350, intangible assets with an indefinite useful economic life are not amortized, but are subject to impairment testing at the reporting unit on an annual basis, or when events or changes in circumstances indicate that the carrying amounts are impaired. An entity may assess qualitative factors to determine whether it is more likely than not (that is, a likelihood of more than 50 percent) that the fair value of a reporting unit is less than its carrying amount, including goodwill (“Step 0”). In evaluating whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, an entity assesses relevant events and circumstances, such as the following: • Macroeconomic conditions, such as a deterioration in general economic conditions, limitations on accessing capital, or other developments in equity and credit markets. • Industry and market considerations, such as a deterioration in the environment in which an entity operates, an increased competitive environment, a decline in market-dependent multiples or metrics (considered in both absolute terms and relative to peers), a change in the market for an entity’s products or services, or a regulatory or political development. • Overall financial performance, such as negative or declining cash flows or a decline in actual or planned revenue or earnings compared with actual and projected results of relevant prior periods. • Other relevant entity-specific events, such as changes in management, key personnel, strategy, or customers; contemplation of bankruptcy; or litigation. • Events affecting a reporting unit, such as a change in the composition or carrying amount of its net assets; a more-likely-than-not expectation of selling or disposing all, or a portion, of a reporting unit; the testing for recoverability of a significant asset group within a reporting unit; or recognition of a goodwill impairment loss in the financial statements of a subsidiary that is a component of a reporting unit. If, after assessing the totality of events or circumstances such as those described in the preceding paragraph, an entity determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then the quantitative goodwill impairment test, as described below, is unnecessary. Goodwill is tested for impairment by estimating the fair value of a reporting unit. Significant judgment is applied when goodwill is assessed for impairment. This judgment includes developing cash flow projections, selecting appropriate discount rates, identifying relevant market comparables, incorporating general economic and market conditions, and selecting an appropriate control premium. The selection and weighting of the various fair value techniques may result in a higher or lower fair value. Judgment is applied in determining the weightings that are most representative of fair value. Quantitative impairment testing requires a comparison of each reporting unit’s fair value to carrying value to identify potential impairment. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, an impairment loss is recognized. In adopting ASU 2017-04, the Company measures that loss as an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. Additionally, the Company considers the income tax effect from any tax deductible goodwill on the carrying amount of the reporting unit, if applicable, when measuring the goodwill impairment loss. The fair value of the reporting unit is determined using generally accepted approaches to valuation commonly referred to as the income approach, market approach, and cost approach. Within each category, a variety of methodologies exist to assist in the estimation of fair value. Generally a valuation consultant will be engaged to assist with the valuation. BPFH has three reportable segments that have goodwill: Wealth Management and Trust, Investment Management, and Wealth Advisory. Boston Private Wealth is the only reporting unit within the Wealth Management and Trust segment. Anchor and DGHM are the reporting units within the Investment Management segment. DGHM does not have any remaining goodwill. BOS and KLS are the reporting units within the Wealth Advisory segment. Discrete financial information is available and segment management regularly reviews the operating results of Anchor, KLS, and BOS, they are all considered reporting units. For the reporting units within the segments, the Company utilizes both the income and market approaches to determine fair value of the reporting units. The income approach is primarily based on discounted cash flows derived from assumptions of income statement activity. For the market approach, earnings before interest, taxes, depreciation and amortization (“EBITDA”) and revenue multiples of comparable companies are selected and applied to the financial services reporting unit’s applicable metrics. The aggregate fair values of the reporting units are compared to market capitalization as an assessment of the appropriateness of the fair value measurements. A control premium analysis is performed to determine whether the implied control premium was within range of overall control premiums observed in the market place. If the carrying amount of the reporting unit’s goodwill is greater than the fair value of the reporting unit’s goodwill, an impairment loss must be recognized for the excess (i.e., recorded goodwill must be written down to the implied fair value of the reporting unit’s goodwill). After a goodwill impairment loss for a reporting unit is measured and recognized, the adjusted carrying amount of the reporting unit’s goodwill becomes the new accounting basis for that goodwill.
Income Tax, Policy [Policy Text Block]	Income Tax Estimates The Company accounts for income taxes in accordance with ASC 740, Income Taxes (“ASC 740”). The deferred tax assets and/or liabilities are determined by multiplying the differences between the financial reporting and tax reporting basis for assets and liabilities by the enacted tax rates expected to be in effect when such differences are recovered or settled. The effect on deferred taxes for a change in tax rates is recognized in income tax expense/ (benefit) attributable to continuing operations in the period that includes the enactment date. Valuation allowances on deferred tax assets are estimated based on our assessment of the realizability of such amounts. Significant management judgment is required in determining the provision for income taxes and, in particular, any valuation allowance recorded against our deferred tax assets. In accordance with ASC 740, deferred tax assets are to be reduced by a valuation allowance if, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The realization of the tax benefit depends upon the existence of sufficient taxable income of the appropriate character within the carry-forward periods. Management considered the following items in evaluating the need for a valuation allowance: ▪ The Company had cumulative pre-tax income, as adjusted for permanent book-to-tax differences, during the period 2015 through 2017. ▪ Deferred tax assets are expected to reverse in periods when there will be taxable income. ▪ The Company projects sufficient future taxable income to be generated by operations during the available carry-forward period. ▪ The Company considered the impact the Tax Act will have on the Company’s ability to generate sufficient taxable income in the carry-forward periods. ▪ Certain tax planning strategies are available, such as reducing investments in tax-exempt securities. ▪ The Company has not had any operating loss or tax credit carryovers expiring unused in recent years. The Company believes that it is more likely than not that the net deferred tax asset as of December 31, 2017 , which has been re-measured at the federal corporate tax rate of 21%, will be realized based primarily upon the ability to generate future taxable income. The Company does not have any capital losses in excess of capital gains as of December 31, 2017.
Derivatives, Policy [Policy Text Block]	Derivative Instruments and Hedging Activities The Company records derivatives on the consolidated balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. Derivatives used to hedge exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives used to hedge exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income/ (loss) (a component of shareholders’ equity), net of tax, and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion, if any, of changes in the fair value of the derivative is recognized directly in earnings. The Company assesses the effectiveness of each hedging relationship by comparing the changes in cash flows of the derivative hedging instrument with the changes in cash flows of the designated hedged transactions. On January 1, 2018, the Company elected to early adopt ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities , under the modified retrospective transition. Under the new ASU, the concept of ineffectiveness will no longer be used. In accordance with the guidance, the Company will recognize all reclassifications out of accumulated other comprehensive income/ (loss) (other than those related to a hedge transaction probable of not occurring) in earnings. For derivatives designated as fair value hedges, changes in the fair value of the derivative are recognized in earnings together with the changes in the fair value of the related hedged item. Therefore, the net amount, if any, representing hedge ineffectiveness, is reflected in earnings.
Management and Investment Advisory Fees, Policy [Policy Text Block]	Investment Management, Wealth Advisory, and Wealth Management and Trust Fees The Company generates fee income from providing wealth management, investment management and wealth advisory services through the Wealth and Investment businesses and from providing trust services to its clients at the Bank. Investment management fees are generally based upon the value of assets under management and are billed monthly, quarterly, or annually. Asset-based advisory fees are recognized as services are rendered and are based upon a percentage of the fair value of client assets managed. Certain wealth advisory fees are not asset-based and are negotiated individually with clients. Any fees collected in advance are deferred and recognized as income over the period earned. Performance-based advisory fees are generally assessed as a percentage of the investment performance realized on a client’s account, generally over an annual period, and are not recognized until any contingencies in the contract that could require the performance fee to be reduced have been eliminated. Assets under management and advisory (“AUM”) at the Company’s consolidated affiliates are not included in the consolidated financial statements since they are held in a fiduciary or agency capacity and are not assets of the Company.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Incentive Plans At December 31, 2017 , the Company has three stock-based incentive compensation plans. These plans encourage and enable the officers, employees, and non-employee directors of the Company to acquire an interest in the Company. The Company accounts for share-based awards in accordance with ASC 718, Compensation – Stock Compensation . Costs resulting from the issuance of such share-based payment awards are required to be recognized in the financial statements based on the grant date fair value of the award. Stock-based compensation expense is recognized over the requisite service period, which is generally the vesting period.
Earnings Per Share, Policy [Policy Text Block]	Earnings Per Share (“EPS”) Basic EPS is computed by dividing net income/ (loss) attributable to common shareholders by the weighted average number of common shares outstanding during the year. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock (such as stock warrants, non-participating performance-based restricted stock, certain time-based restricted stock, and stock options, among others) were exercised or converted into additional common shares that would then share in the earnings of the entity. Diluted EPS is computed by dividing net income attributable to common shareholders by the weighted average number of common shares outstanding for the year, plus an incremental number of common-equivalent shares computed using the treasury stock method. Dilutive potential common shares could consist of: stock options, performance-based restricted stock, time-based restricted stock not participating in common stock dividends, warrants or other dilutive securities, and conversion of the convertible trust preferred securities. Additionally, when dilutive, interest expense (net of tax) related to the convertible trust preferred securities is added back to net income attributable to common shareholders. The calculation of diluted EPS excludes the potential dilution of common shares and the inclusion of any related expenses if the effect is antidilutive. Unvested time-based restricted stock issued prior to 2013, which includes the right to receive non-forfeitable dividends, is considered to participate with common stock in undistributed earnings for purposes of computing EPS. Companies such as BPFH that have such participating securities are required to calculate basic EPS using the two-class method and diluted EPS using the more dilutive amount resulting from the application of either the two-class method or the if-converted method. Calculations of basic and diluted EPS under the two-class method (i) exclude from the numerator any dividends paid or owed on participating securities and any undistributed earnings considered to be attributable to participating securities, and (ii) exclude from the denominator the dilutive impact of the participating securities. Calculations of EPS under the if-converted method (i) include in the numerator any dividends paid or owed on participating securities, and (ii) include the dilutive impact of the participating securities using the treasury stock method. In 2013, the Company adjusted its time-based restricted stock grant agreements so that dividends would be accumulated and paid only upon vesting, only as to the amount of shares that vest. As a result of this adjustment, time-based restricted stock granted in or after 2013 no longer contains a right to receive non-forfeitable dividends, and therefore is not considered a participating security for purposes of the EPS calculation. Time-based restricted stock issued prior to 2013 was not modified and was still considered a participating security until it vested or was forfeited or canceled. All remaining time-based restricted stock issued prior to 2013 was fully vested, forfeited, or canceled during 2016. For the calculation of the Company’s EPS, see Part II. Item 8. “Financial Statements and Supplementary Data - Note 16: Earnings Per Share.”
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”). ASU 2014-09 replaces existing revenue recognition standards and expands the disclosure requirements for revenue agreements with customers. ASU 2014-09 has been subsequently amended by additional ASUs, including ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) and ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, collectively, “ASU 2014-09 et al. ” Under the new standard, a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration which the company expects to receive in exchange for those goods or services. ASU 2014-09 et al. does not apply to revenue associated with financial instruments such as loans and securities. Therefore, the Company’s net interest income will not be impacted by this new standard. The Company assembled a project team to address the changes pursuant to ASU 2014-09 et al. The project team completed the scope assessment and determined that approximately 60% of our revenue, including all of our interest income and a portion of our noninterest income, is out of scope of the guidance. The contracts that are in scope of the guidance are primarily related to service charges and fees on deposit accounts, wealth management and trust income, wealth advisory income, investment management income, and other service charges, commissions and fees. Our review of these contracts has not identified any material changes in the timing of revenue recognition. On January 1, 2018, we adopted ASU 2014-09 et al. using the modified retrospective transition method, however no cumulative effect adjustment to opening retained earnings as of January 1, 2018 was required. The Company does expect additional financial statement disclosures and associated internal controls to be implemented along with the adoption of this ASU. In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Instruments - Going Concern (“ASU 2014-15”). ASU 2014-15 requires management to evaluate an entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. Management must evaluate whether conditions and events raise substantial doubt about an entity’s ability to continue as a going concern and then whether its plans alleviate that doubt. ASU 2014-15 was effective in 2016 and management performed the required evaluation and concluded that there were no such conditions or events that raised substantial doubt about the Company’s ability to continue as a going concern. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) . This ASU update amends current lease accounting and requires all leases, other than short-term leases, to be reported on the balance sheet through the recognition of a right-of-use asset and a corresponding liability for future lease obligations. The amended guidance will be effective for fiscal years beginning after December 15, 2018, including interim periods within those annual periods and will require transition utilizing a modified retrospective approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption of this ASU is permitted although the Company does not plan to early adopt. The Company does not anticipate a material impact to revenue or operating expenses as a result of the adoption of this ASU. The Company expects that this ASU will gross up the assets and liabilities on the balance sheet related to the lease assets and liabilities and reduce regulatory capital ratios. In March 2016, the FASB issued ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting . This update is intended to simplify several aspects of the accounting for employee share-based plans such as income tax consequences, classification of awards as either liabilities or equity on the balance sheet, and classification on the statement of cash flows. This ASU was effective for fiscal years beginning after December 15, 2016, including interim periods within those years. The Company adopted this ASU on January 1, 2017. The adoption of this ASU has resulted in, and will continue to result in, fluctuations in the Company’s earnings due to changes in the Company’s stock price between issuance date and settlement date of employee share-based transactions. In addition, the Company anticipates that certain stock options will expire unexercised, due to being out of the money, and this ASU requires the previous tax benefits to be reversed. For the year ended December 31, 2017, the impact on the Company’s income tax expense related to the adoption of this ASU was a decrease of $0.3 million . In June 2016, the FASB issued ASU 2016-13, Financial Instruments (Topic 326) (“ASU 2016-13”). This update is intended to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. This ASU will be effective for fiscal years beginning after December 15, 2019. Early adoption is available as of the fiscal year beginning after December 15, 2018. The Company does not plan on adopting early. The impact of this ASU on the Company’s consolidated financial statements will depend on factors at the time of adoption such as the balance and type of loans on the balance sheet, the Company’s loan loss history, and various qualitative factors. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) (“ASU 2016-15”). This update is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. This ASU is effective for fiscal years beginning after December 15, 2017, and interim periods within those years. Early adoption is permitted, provided that all of the amendments are adopted in the same period, however the Company did not early adopt. The guidance requires application using a retrospective transition method. The Company does not expect that this ASU will have a significant impact on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-04. This update is the result of the first phase of a two phase project by the FASB to reduce the cost and complexity of the goodwill impairment test. The objective of Phase 1 of the project, which resulted in ASU 2017-04, is to simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Instead, under the amendments in ASU 2017-04, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. Under the provisions of this update, an entity still has the option to perform the qualitative assessment, or Step 0 test, for a reporting unit to determine if the quantitative impairment test is necessary. This ASU will be effective for any annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019, with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company elected to early adopt this ASU as of January 1, 2017. The adoption of this ASU could increase or decrease the amount of a goodwill impairment charge should any of the Company’s reporting units with goodwill fail a Step 1 test, as compared to the amount of a goodwill impairment charge under the existing standards depending on the fair value of the reporting unit’s assets. In March 2017, the FASB issued ASU 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities (“ASU 2017-08”). This update amends the amortization period for certain purchased callable debt securities held at a premium. The amortization period for the premium on such securities is being shortened to the earliest call date. Under current GAAP, entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument. ASU 2017-08 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years. Early adoption is permitted, including in an interim period. The guidance requires application using a modified retrospective transition method through a cumulative-effect adjustment to beginning retained earnings. The Company early adopted this ASU as of July 1, 2017, which had a minimal impact on the consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). The standard is intended to improve the transparency and understandability of information conveyed to financial statement users about an entity’s risk management activities by better aligning the entity’s financial reporting for hedging relationships with those risk management activities and to reduce the complexity of and simplify the application of hedge accounting by preparers. ASU No. 2017-12 is effective for interim and annual reporting periods beginning after December 15, 2018; early adoption is permitted. The Company elected to early adopt this ASU as of January 1, 2018 with a modified retrospective transition. The Company currently has six interest rate swaps that are designated for hedge accounting and the adoption is not expected to have a significant impact on the consolidated financial statements. This ASU will provide more flexibility in the Company’s risk management activities and we believe it will enhance the Company’s ability to employ risk management strategies, while improving the transparency and understanding of those strategies for financial statement users. In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . This update was issued to address a narrow-scope financial reporting issue that arose as a consequence of the change in the tax law. On December 22, 2017, the U.S. federal government enacted the Tax Cuts and Jobs Act (the “Tax Act”) which, among other significant changes, lowers the federal corporate tax rate from 35% to 21% effective January 1, 2018. This update requires a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the enactment of the Tax Act. ASC 740 requires that the tax effects of changes in tax rates be recognized in income tax expense/ (benefit) attributable to continuing operations in the period in which the law is enacted. As a result, the tax effect of accumulated other comprehensive income does not reflect the appropriate tax rate. The amendments in this ASU would eliminate the stranded tax effects associated with the change in the federal corporate income tax rate related to the Tax Act and would improve the usefulness of information reported to financial statement users. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those years. Early adoption is permitted for public business entities for reporting periods for which financial statements have not yet been issued. The Company adopted this ASU on December 31, 2017 and made a one-time reclassification of $1.5 million from accumulated other comprehensive income to retained earnings, which is reflected in the consolidated statement of changes in shareholders’ equity.

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Cost [Table Text Block]	The following table presents a summary of the restructuring activity for the years ended December 31, 2017, 2016 and 2015. Severance Charges Other Associated Costs Total (In thousands) Accrued charges at December 31, 2014 $ 739 $ — $ 739 Costs incurred 3,434 290 3,724 Costs paid (868 ) (290 ) (1,158 ) Accrued charges at December 31, 2015 3,305 — 3,305 Costs incurred 2,017 — 2,017 Costs paid (3,345 ) — (3,345 ) Accrued charges at December 31, 2016 1,977 — 1,977 Costs incurred — — — Costs paid (1,640 ) — (1,640 ) Accrued charges at December 31, 2017 $ 337 $ — $ 337

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Investments [Abstract]
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	The following tables present a summary of investment securities: Amortized Cost Unrealized Fair Value Gains Losses (In thousands) At December 31, 2017: Available-for-sale securities at fair value: U.S. government and agencies $ 35,132 $ — $ (833 ) $ 34,299 Government-sponsored entities 305,101 22 (2,622 ) 302,501 Municipal bonds 299,647 4,559 (1,148 ) 303,058 Mortgage-backed securities (1) 521,753 491 (12,568 ) 509,676 Other 20,794 — — 20,794 Total $ 1,182,427 $ 5,072 $ (17,171 ) $ 1,170,328 Held-to-maturity securities at amortized cost: Mortgage-backed securities (1) $ 74,576 $ — $ (795 ) $ 73,781 Total $ 74,576 $ — $ (795 ) $ 73,781 Amortized Cost Unrealized Fair Value Gains Losses (In thousands) At December 31, 2016: Available-for-sale securities at fair value: U.S. government and agencies $ 40,704 $ 86 $ (854 ) $ 39,936 Government-sponsored entities 337,865 1,058 (2,259 ) 336,664 Municipal bonds 296,271 2,116 (4,990 ) 293,397 Mortgage-backed securities (1) 584,960 928 (15,561 ) 570,327 Other 23,361 447 — 23,808 Total $ 1,283,161 $ 4,635 $ (23,664 ) $ 1,264,132 Held-to-maturity securities at amortized cost: Mortgage-backed securities (1) $ 93,079 $ 1 $ (476 ) $ 92,604 Total $ 93,079 $ 1 $ (476 ) $ 92,604 _________________ (1) All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.
Investments Classified by Contractual Maturity Date [Table Text Block]	The following tables present the maturities of available-for-sale investment securities, based on contractual maturity, and the weighted average yields of such securities as of December 31, 2017 : U.S. government and agencies (1) Government-sponsored entities (1) Amortized cost Fair value Weighted average yield Amortized cost Fair value Weighted average yield (In thousands) Within one year $ — $ — — % $ 44,033 $ 43,967 1.39 % After one, but within five years 15,192 15,105 1.53 % 224,747 223,315 1.86 % After five, but within ten years 19,940 19,194 1.73 % 36,321 35,219 2.05 % Greater than ten years — — — % — — — % Total $ 35,132 $ 34,299 1.64 % $ 305,101 $ 302,501 1.81 % Municipal bonds (1) Mortgage-backed securities (2) Amortized cost Fair value Weighted average yield (3) Amortized cost Fair value Weighted average yield (In thousands) Within one year $ 15,770 $ 15,756 1.85 % $ 17 $ 17 2.33 % After one, but within five years 57,178 57,260 2.63 % 11,460 11,407 2.25 % After five, but within ten years 33,979 34,719 3.73 % 236,360 229,770 2.18 % Greater than ten years 192,720 195,323 4.07 % 273,916 268,482 2.10 % Total $ 299,647 $ 303,058 3.64 % $ 521,753 $ 509,676 2.14 % Other (4) Amortized cost Fair value Weighted average yield (In thousands) Within one year $ 20,794 $ 20,794 — % After one, but within five years — — — % After five, but within ten years — — — % Greater than ten years — — — % Total $ 20,794 $ 20,794 — % The following table presents the maturities of held-to-maturity investment securities, based on contractual maturity, and the weighted average yields of such securities as of December 31, 2017 : Mortgage-backed securities (2) Amortized cost Fair value Weighted average yield (In thousands) Within one year $ — $ — — % After one, but within five years — — — % After five, but within ten years 16,722 16,551 2.17 % Greater than ten years 57,854 57,230 2.30 % Total $ 74,576 $ 73,781 2.27 % ___________________ (1) Certain securities are callable before their final maturity. (2) Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives. (3) Yields shown on a fully taxable equivalent (“FTE”) basis. The tax rate used in the table above was the tax rate in effect on December 31, 2017. The recent enactment of the Tax Act will reduce the rate applied in future periods, which will result in a lower FTE yield. (4) Other securities consist of money market mutual funds and equity securities held by certain Wealth Advisory and Investment Management businesses.
Realized Gain (Loss) on Investments [Table Text Block]	The following table presents the proceeds from sales, gross realized gains and gross realized losses for available-for-sale investment securities that were sold during the following years: Year Ended December 31, 2017 2016 2015 (In thousands) Proceeds from sales $ 148,407 $ 50,049 $ 34,160 Realized gains 519 522 272 Realized losses (143 ) (1 ) (36 )
Schedule of Unrealized Loss on Investments [Table Text Block]	The following tables present information regarding securities at December 31, 2017 and 2016 having temporary impairment, due to the fair values having declined below the amortized cost of the individual securities, and the time period that the investments have been temporarily impaired. Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses # of securities (In thousands, except number of securities) December 31, 2017 Available-for-sale securities U.S. government and agencies $ 14,902 $ (79 ) $ 19,397 $ (754 ) $ 34,299 $ (833 ) 6 Government-sponsored entities 220,275 (1,350 ) 38,273 (1,272 ) 258,548 (2,622 ) 36 Municipal bonds 46,112 (131 ) 50,842 (1,017 ) 96,954 (1,148 ) 63 Mortgage-backed securities (1) 97,117 (903 ) 386,785 (11,665 ) 483,902 (12,568 ) 103 Total $ 378,406 $ (2,463 ) $ 495,297 $ (14,708 ) $ 873,703 $ (17,171 ) 208 Held-to-maturity securities Mortgage-backed securities (1) $ 59,218 $ (534 ) $ 14,563 $ (261 ) $ 73,781 $ (795 ) 16 Total $ 59,218 $ (534 ) $ 14,563 $ (261 ) $ 73,781 $ (795 ) 16 Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses # of securities (In thousands, except number of securities) December 31, 2016 Available-for-sale securities U.S. government and agencies $ 19,094 $ (838 ) $ 643 $ (16 ) $ 19,737 $ (854 ) 4 Government-sponsored entities 125,412 (2,259 ) — — 125,412 (2,259 ) 18 Municipal bonds 182,395 (4,957 ) 2,720 (33 ) 185,115 (4,990 ) 109 Mortgage-backed securities (1) 492,008 (13,988 ) 41,544 (1,573 ) 533,552 (15,561 ) 99 Total $ 818,909 $ (22,042 ) $ 44,907 $ (1,622 ) $ 863,816 $ (23,664 ) 230 Held-to-maturity securities Mortgage-backed securities (1) $ 87,483 $ (476 ) $ — $ — $ 87,483 $ (476 ) 15 Total $ 87,483 $ (476 ) $ — $ — $ 87,483 $ (476 ) 15 ___________________ (1) All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.
Concentration Risk Disclosure [Text Block]	The following table presents the concentration of securities with any one issuer that exceeds ten percent of shareholders’ equity as of December 31, 2017 : Amortized cost Fair value (In thousands) Government National Mortgage Association $ 104,188 $ 101,941 Federal Home Loan Mortgage Corporation 349,926 342,374 Federal Home Loan Bank 163,151 161,747 Federal National Mortgage Association 259,108 255,143 Total $ 876,373 $ 861,205

Loans Receivable and Credit Q38

Loans Receivable and Credit Quality (Tables)	12 Months Ended
	Dec. 31, 2017
Loans Receivable [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	The following table presents a summary of the loan portfolio based on the portfolio segment as of the dates indicated: December 31, 2017 December 31, 2016 (In thousands) Commercial and industrial $ 520,992 $ 611,370 Commercial tax-exempt 418,698 398,604 Total commercial and industrial 939,690 1,009,974 Commercial real estate 2,440,220 2,302,244 Construction and land 164,990 104,839 Residential 2,682,533 2,379,861 Home equity 99,958 118,817 Consumer and other 177,637 198,619 Total $ 6,505,028 $ 6,114,354
Schedule of Financing Receivables, Non Accrual Status [Table Text Block]	The following table presents nonaccrual loans receivable by class of receivable as of the dates indicated: December 31, 2017 December 31, 2016 (In thousands) Commercial and industrial $ 748 $ 572 Commercial tax-exempt — — Total commercial and industrial 748 572 Commercial real estate 1,985 4,583 Construction and land 110 179 Residential 8,470 10,908 Home equity 2,840 1,072 Consumer and other 142 1 Total $ 14,295 $ 17,315
Past Due Financing Receivables [Table Text Block]	The following tables present the payment status of loans receivable by class of receivable as of the dates indicated: December 31, 2017 Accruing Past Due Nonaccrual Loans 30-59 Days Past Due 60-89 Days Past Due Total Accruing Past Due Current 30-89 Days Past Due 90 Days or Greater Past Due Total Non- accrual Loans Current Accruing Loans Total Loans Receivable (In thousands) Commercial and industrial $ 10,903 $ 849 $ 11,752 $ 355 $ — $ 393 $ 748 $ 508,492 $ 520,992 Commercial tax-exempt — — — — — — — 418,698 418,698 Commercial real estate 4,043 — 4,043 163 — 1,822 1,985 2,434,192 2,440,220 Construction and land — — — — — 110 110 164,880 164,990 Residential 7,239 1,635 8,874 805 3,172 4,493 8,470 2,665,189 2,682,533 Home equity 355 — 355 — 71 2,769 2,840 96,763 99,958 Consumer and other 24 — 24 17 125 — 142 177,471 177,637 Total $ 22,564 $ 2,484 $ 25,048 $ 1,340 $ 3,368 $ 9,587 $ 14,295 $ 6,465,685 $ 6,505,028 December 31, 2016 Accruing Past Due Nonaccrual Loans 30-59 60-89 Total Current 30-89 90 Days Total Current Total (In thousands) Commercial and industrial $ 541 $ 1,078 $ 1,619 $ 537 $ — $ 35 $ 572 $ 609,179 $ 611,370 Commercial tax-exempt — — — — — — — 398,604 398,604 Commercial real estate 3,096 — 3,096 2,311 835 1,437 4,583 2,294,565 2,302,244 Construction and land — — — 129 12 38 179 104,660 104,839 Residential 3,646 536 4,182 2,148 1,274 7,486 10,908 2,364,771 2,379,861 Home equity 245 — 245 — 80 992 1,072 117,500 118,817 Consumer and other 5,995 — 5,995 1 — — 1 192,623 198,619 Total $ 13,523 $ 1,614 $ 15,137 $ 5,126 $ 2,201 $ 9,988 $ 17,315 $ 6,081,902 $ 6,114,354
Financing Receivable Credit Quality Indicators [Table Text Block]	The following tables present the loan portfolio’s credit risk profile by internally assigned grade and class of receivable as of the dates indicated: December 31, 2017 By Loan Grade or Nonaccrual Status Pass Special Accruing Nonaccrual Total (In thousands) Commercial and industrial $ 496,395 $ 12,898 $ 10,951 $ 748 $ 520,992 Commercial tax-exempt 413,139 5,559 — — 418,698 Commercial real estate 2,346,833 56,947 34,455 1,985 2,440,220 Construction and land 146,514 11,770 6,596 110 164,990 Residential 2,672,714 — 1,349 8,470 2,682,533 Home equity 97,118 — — 2,840 99,958 Consumer and other 177,494 — 1 142 177,637 Total $ 6,350,207 $ 87,174 $ 53,352 $ 14,295 $ 6,505,028 December 31, 2016 By Loan Grade or Nonaccrual Status Pass Special Mention Accruing Substandard Nonaccrual Loans Total (In thousands) Commercial and industrial $ 591,388 $ 10,133 $ 9,277 $ 572 $ 611,370 Commercial tax-exempt 388,544 10,060 — — 398,604 Commercial real estate 2,230,732 17,233 49,696 4,583 2,302,244 Construction and land 101,254 109 3,297 179 104,839 Residential 2,367,554 — 1,399 10,908 2,379,861 Home equity 117,745 — — 1,072 118,817 Consumer and other 198,616 — 2 1 198,619 Total $ 5,995,833 $ 37,535 $ 63,671 $ 17,315 $ 6,114,354
Impaired Financing Receivables [Table Text Block]	The following tables present, by class of receivable, the balance of impaired loans with and without a related allowance, the associated allowance for those impaired loans with a related allowance, and the total unpaid principal on impaired loans: As of and for the year ended December 31, 2017 Recorded Investment (1) Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized while Impaired (In thousands) With no related allowance recorded: Commercial and industrial $ 1,434 $ 2,238 n/a $ 1,594 $ 50 Commercial tax-exempt — — n/a 1,001 80 Commercial real estate 1,832 3,453 n/a 3,098 1,546 Construction and land 109 109 n/a 172 — Residential 9,337 9,709 n/a 9,033 360 Home equity 1,779 1,779 n/a 413 — Consumer and other — — n/a — — Subtotal $ 14,491 $ 17,288 n/a $ 15,311 $ 2,036 With an allowance recorded: Commercial and industrial $ 242 $ 242 $ 58 $ 156 $ 4 Commercial tax-exempt — — — — — Commercial real estate 6,855 7,284 362 6,980 322 Construction and land — — — — — Residential 828 828 89 2,469 89 Home equity 36 36 20 36 1 Consumer and other 125 250 125 10 — Subtotal $ 8,086 $ 8,640 $ 654 $ 9,651 $ 416 Total: Commercial and industrial $ 1,676 $ 2,480 $ 58 $ 1,750 $ 54 Commercial tax-exempt — — — 1,001 80 Commercial real estate 8,687 10,737 362 10,078 1,868 Construction and land 109 109 — 172 — Residential 10,165 10,537 89 11,502 449 Home equity 1,815 1,815 20 449 1 Consumer and other 125 250 125 10 — Total $ 22,577 $ 25,928 $ 654 $ 24,962 $ 2,452 ___________________ (1) Recorded investment represents the client loan balance net of historical charge-offs and historical nonaccrual interest paid, which was applied to principal. As of and for the year ended December 31, 2016 Recorded Investment (1) Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized while Impaired (In thousands) With no related allowance recorded: Commercial and industrial $ 1,793 $ 2,155 n/a $ 5,288 $ 249 Commercial tax-exempt — — n/a — — Commercial real estate 4,488 9,647 n/a 8,520 1,032 Construction and land 179 507 n/a 1,069 48 Residential 8,134 8,506 n/a 7,446 211 Home equity — — n/a — — Consumer and other — — n/a — — Subtotal $ 14,594 $ 20,815 n/a $ 22,323 $ 1,540 With an allowance recorded: Commercial and industrial $ — $ — $ — $ 31 $ 1 Commercial tax-exempt — — — — — Commercial real estate 7,115 7,544 548 7,230 314 Construction and land — — — 507 — Residential 4,284 4,284 565 5,505 143 Home equity 37 37 22 3 — Consumer and other — — — — — Subtotal $ 11,436 $ 11,865 $ 1,135 $ 13,276 $ 458 Total: Commercial and industrial $ 1,793 $ 2,155 $ — $ 5,319 $ 250 Commercial tax-exempt — — — — — Commercial real estate 11,603 17,191 548 15,750 1,346 Construction and land 179 507 — 1,576 48 Residential 12,418 12,790 565 12,951 354 Home equity 37 37 22 3 — Consumer and other — — — — — Total $ 26,030 $ 32,680 $ 1,135 $ 35,599 $ 1,998 ____________________ (1) Recorded investment represents the client loan balance net of historical charge-offs and historical nonaccrual interest paid, which was applied to principal.
Troubled Debt Restructurings on Financing Receivables [Table Text Block]	The following tables present the balance of TDRs that were restructured or defaulted during the periods indicated: As of and for the year ended December 31, 2017 Restructured Year to Date TDRs that defaulted that were restructured in prior twelve months # of Loans Pre- modification recorded investment Post- # of Loans Post- modification recorded investment (In thousands, except number of loans) Commercial and industrial — $ — $ — — $ — Commercial tax-exempt — — — — — Commercial real estate — — — — — Construction and land — — — — — Residential (1) 1 108 109 — — Home equity — — — — — Consumer and other — — — — — Total 1 $ 108 $ 109 — $ — ____________________ (1) Represents the following concession: temporary rate reduction. As of and for the year ended December 31, 2016 Restructured Year to Date TDRs that defaulted that were restructured in prior twelve months # of Loans Pre- modification recorded investment Post- # of Loans Post- modification recorded investment (In thousands, except number of loans) Commercial and industrial 3 $ 7,384 $ 7,209 — $ — Commercial tax-exempt — — — — — Commercial real estate 1 1,276 1,276 1 1,276 Construction and land — — — — — Residential 5 1,709 1,721 — — Home equity — — — — — Consumer and other — — — — — Total 9 $ 10,369 $ 10,206 1 $ 1,276 As of and for the year ended December 31, 2016 Extension of Term Temporary Rate Reduction Payment Deferral Combination of Concessions (1) Total Concessions # of Loans Post- # of Loans Post- # of Loans Post- # of Loans Post- # of Loans Post- (In thousands, except number of loans) Commercial and Industrial 2 $ 7,209 — $ — — $ — 1 $ — 3 $ 7,209 Commercial tax-exempt — — — — — — — — — — Commercial real estate — — — — — — 1 1,276 1 1,276 Construction and Land — — — — — — — — — — Residential — — 4 519 1 1,202 — — 5 1,721 Home Equity — — — — — — — — — — Consumer and other — — — — — — — — — — ____________________ (1) Combination of concessions includes loans that have had more than one modification, including extension of term, temporary reduction of interest rate, and/or payment deferral.

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Allowance for Loan Losses [Abstract]
Allowance for Credit Losses on Financing Receivables [Table Text Block]	The following table presents a summary of the changes in the allowance for loan losses for the periods indicated: As of and for the year ended December 31, 2017 2016 2015 (In thousands) Allowance for loan losses, beginning of year: Commercial and industrial $ 12,751 $ 15,814 $ 14,114 Commercial real estate 50,412 44,215 43,854 Construction and land 3,039 6,322 4,041 Residential 10,449 10,544 10,374 Home equity 1,035 1,085 1,003 Consumer and other 391 520 382 Unallocated (1) — — 2,070 Total allowance for loan losses, beginning of year 78,077 78,500 75,838 Loans charged-off: Commercial and industrial (393 ) (2,851 ) (253 ) Commercial real estate — — (1,400 ) Construction and land — (400 ) — Residential (58 ) (605 ) (313 ) Home equity — — — Consumer and other (412 ) (93 ) (70 ) Total charge-offs (863 ) (3,949 ) (2,036 ) Recoveries on loans previously charged-off: Commercial and industrial 472 3,212 2,471 Commercial real estate 4,621 6,040 2,482 Construction and land 25 1,117 1,158 Residential 47 65 141 Home equity — — — Consumer and other 32 27 1 Total recoveries 5,197 10,461 6,253 Provision/ (credit) for loan losses: Commercial and industrial (1,095 ) (3,424 ) (518 ) Commercial real estate (8,213 ) 157 (721 ) Construction and land 1,885 (4,000 ) 1,123 Residential (665 ) 445 342 Home equity (200 ) (50 ) 82 Consumer and other 619 (63 ) 207 Unallocated (1) — — (2,070 ) Total provision/(credit) for loan losses (7,669 ) (6,935 ) (1,555 ) As of and for the year ended December 31, 2017 2016 2015 (In thousands) Allowance for loan losses at December 31 (end of year): Commercial and industrial 11,735 12,751 15,814 Commercial real estate 46,820 50,412 44,215 Construction and land 4,949 3,039 6,322 Residential 9,773 10,449 10,544 Home equity 835 1,035 1,085 Consumer and other 630 391 520 Total allowance for loan losses at December 31 (end of year) $ 74,742 $ 78,077 $ 78,500 __________________ (1) As of December 31, 2015, the unallocated reserve was allocated to the qualitative factors as part of the general reserve (ASC 450). The allocation had no effect on the 2015 provision/ (credit) for loan losses. The provision/ (credit) for loan losses and related balance in the allowance for loan losses for tax-exempt commercial and industrial loans are included with commercial and industrial. The provision/ (credit) for loan losses and related balance in the allowance for loan losses for tax-exempt commercial real estate loans are included with commercial real estate. There were no charge-offs or recoveries, for any period presented, for both commercial and industrial and commercial real estate tax-exempt loans. The following tables present the Company’s allowance for loan losses and loan portfolio at December 31, 2017 and 2016 by portfolio segment, disaggregated by method of analysis. The Company had no loans acquired with deteriorated credit quality at December 31, 2017 or 2016 . December 31, 2017 Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Recorded investment (loan balance) Allowance for loan losses Recorded Allowance Recorded Allowance (In thousands) Commercial and industrial $ 1,676 $ 58 $ 938,014 $ 11,677 $ 939,690 $ 11,735 Commercial real estate 8,687 362 2,431,533 46,458 2,440,220 46,820 Construction and land 109 — 164,881 4,949 164,990 4,949 Residential 10,165 89 2,672,368 9,684 2,682,533 9,773 Home equity 1,815 20 98,143 815 99,958 835 Consumer 125 125 177,512 505 177,637 630 Total $ 22,577 $ 654 $ 6,482,451 $ 74,088 $ 6,505,028 $ 74,742 December 31, 2016 Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Recorded Allowance Recorded Allowance Recorded Allowance (In thousands) Commercial and industrial $ 1,793 $ — $ 1,008,181 $ 12,751 $ 1,009,974 $ 12,751 Commercial real estate 11,603 548 2,290,641 49,864 2,302,244 50,412 Construction and land 179 — 104,660 3,039 104,839 3,039 Residential 12,418 565 2,367,443 9,884 2,379,861 10,449 Home equity 37 22 118,780 1,013 118,817 1,035 Consumer — — 198,619 391 198,619 391 Total $ 26,030 $ 1,135 $ 6,088,324 $ 76,942 $ 6,114,354 $ 78,077

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
PREMISES AND EQUIPMENT [Abstract]
Property, Plant and Equipment [Table Text Block]	Premises and equipment consisted of the following: As of December 31, 2017 2016 (In thousands) Leasehold improvements $ 51,161 $ 46,031 Furniture, fixtures, and equipment 39,618 53,156 Buildings 3,159 3,159 Subtotal 93,938 102,346 Less: accumulated depreciation and amortization 56,298 70,519 Premises and equipment, net $ 37,640 $ 31,827
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	The Company is obligated for minimum payments under non-cancelable operating leases. In accordance with the terms of these leases, the Company is currently committed to minimum annual payments as follows: Minimum lease payments (In thousands) 2018 $ 21,066 2019 20,504 2020 19,718 2021 19,460 2022 19,221 Thereafter 58,076 Total $ 158,045

Goodwill and Other Intangible41

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
GOODWILL AND OTHER INTANGIBLE ASSETS [Abstract]
Schedule of Goodwill [Table Text Block]	The following tables detail the changes in carrying value of goodwill by segment during the years ended December 31, 2017 and 2016 . There were no changes in the carrying value of goodwill during 2015. As of December 31, 2015 Impairment As of December 31, 2016 (In thousands) Goodwill Private Banking $ — $ — $ — Wealth Management and Trust 44,305 (9,528 ) 34,777 Investment Management 66,955 — 66,955 Wealth Advisory 40,822 — 40,822 Total goodwill $ 152,082 $ (9,528 ) $ 142,554 As of December 31, 2016 Impairment Adjustments or Reclasses As of December 31, 2017 (In thousands) Goodwill Private Banking $ — $ — $ — $ — Wealth Management and Trust 34,777 — — 34,777 Investment Management (1) 66,955 (24,901 ) (42,054 ) — Wealth Advisory (2) 40,822 — (1 ) 40,821 Total goodwill $ 142,554 $ (24,901 ) $ (42,055 ) $ 75,598 ___________________ (1) Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017. (2) Adjusted for rounding.
Schedule of Intangible Assets and Goodwill [Table Text Block]	The following tables detail total goodwill and the cumulative impairment charges thereon as of December 31, 2017 and 2016 : Goodwill prior to impairment Cumulative goodwill impairment Goodwill (In thousands) Private Banking $ 34,281 $ (34,281 ) $ — Wealth Management and Trust 44,305 (9,528 ) 34,777 Investment Management (1) 75,162 (75,162 ) — Wealth Advisory (2) 40,821 — 40,821 Total goodwill at December 31, 2017 $ 194,569 $ (118,971 ) $ 75,598 Private Banking $ 34,281 $ (34,281 ) $ — Wealth Management and Trust 44,305 (9,528 ) 34,777 Investment Management 117,216 (50,261 ) 66,955 Wealth Advisory 40,822 — 40,822 Total goodwill at December 31, 2016 $ 236,624 $ (94,070 ) $ 142,554 ___________________ (1) Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017. (2) Adjusted for rounding.
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following table shows the gross and net carrying amounts of identifiable intangible assets at December 31, 2017 and 2016 : 2017 2016 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net (In thousands) Advisory contracts (1) $ 37,313 $ 21,370 $ 15,943 $ 71,513 $ 46,828 $ 24,685 Trade names (1) 140 — 140 2,040 — 2,040 Total $ 37,453 $ 21,370 $ 16,083 $ 73,553 $ 46,828 $ 26,725 ___________________ (1) Intangible assets of Anchor are classified as held for sale as of December 31, 2017.
Schedule of Expected Amortization Expense [Table Text Block]	The estimated annual amortization expense for these identifiable intangibles over the next five years is: Estimated intangible amortization expense (In thousands) 2018 $ 2,970 2019 2,848 2020 2,588 2021 2,110 2022 2,056

Derivatives and Hedging Activ42

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table presents the fair value of the Company’s derivative financial instruments as well as their classification on the consolidated balance sheets as of December 31, 2017 and 2016 . December 31, 2017 December 31, 2016 Asset derivatives Liability derivatives Asset derivatives Liability derivatives Balance sheet location Fair value (1) Balance sheet location Fair Balance sheet location Fair Balance sheet location Fair (In thousands) Derivatives designated as hedging instruments: Interest rate products Other assets $ 555 Other liabilities $ (80 ) Other assets $ — Other liabilities $ (1,040 ) Derivatives not designated as hedging instruments: Interest rate products Other assets 18,575 Other liabilities (18,953 ) Other assets 17,032 Other liabilities (16,560 ) Foreign exchange contracts Other assets 2 Other liabilities (2 ) Other assets — Other liabilities — Risk participation agreements Other assets 1 Other liabilities (108 ) Other assets 15 Other liabilities (6 ) Total $ 19,133 $ (19,143 ) $ 17,047 $ (17,606 ) ___________________ (1) For additional details, see Part II. Item 8. “Financial Statements and Supplementary Data - Note 21: Fair Value of Financial Instruments.”
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	The following table presents the effect of the Company’s derivative financial instruments in the consolidated statement of operations for the years ended December 31, 2017 and 2016 . Derivatives in Cash Flow Hedging Relationships Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) (1) Years Ended December 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)Years Ended December 31, 2017 2016 2017 2016 (In thousands) Interest rate products $ 336 $ (799 ) Interest Expense $ (1,168 ) $ (1,672 ) Total $ 336 $ (799 ) $ (1,168 ) $ (1,672 ) ___________________ (1) There was an additional $(11) thousand loss related to the ineffective portion for the year ended December 31, 2017 and an additional $6 thousand gain related to the ineffective portion for the year ended December 31, 2016.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents the effect of the Bank’s derivative financial instruments, not designated as hedging instruments, in the consolidated statements of operations for the years ended December 31, 2017 and 2016 . Derivatives Not Designated as Hedging Instruments Location of Gain or (Loss) Recognized in Income on Derivatives Amount of Gain or (Loss), Net, Recognized in Income on Derivatives for Years Ended December 31, 2017 2016 (In thousands) Interest rate products Other income/(expense) $ (851 ) $ 596 Risk participation agreements Other income/(expense) 354 4 Total $ (497 ) $ 600

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Schedule of Deposits by Type [Table Text Block]	Deposits are summarized as follows: December 31, 2017 2016 (In thousands) Demand deposits (non-interest bearing) $ 2,025,690 $ 1,753,648 Savings and NOW (1) 716,296 652,819 Money market (1) 3,121,811 3,102,048 Certificates of deposit under $100,000 (1) 250,070 236,001 Certificates of deposit $100,000 or more to less than $250,000 (1) 82,665 100,570 Certificates of deposit $250,000 or more 313,714 240,060 Total $ 6,510,246 $ 6,085,146 ___________________ (1) Includes brokered deposits.
Banking and Thrift Disclosure [Text Block]	Certificates of deposit had the following schedule of maturities: December 31, 2017 2016 (In thousands) Less than 3 months remaining $ 214,594 $ 140,304 3 to 6 months remaining 183,780 73,522 6 to 12 months remaining 133,873 213,802 Total due within 1 year 532,247 427,628 1 to 2 years remaining 79,926 115,099 2 to 3 years remaining 32,165 14,492 3 to 4 years remaining 2,083 17,437 4 to 5 years remaining 25 1,972 More than 5 years remaining 3 3 Total $ 646,449 $ 576,631

Federal Funds Purchased and S44

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Schedule of Short-term Debt [Table Text Block]	Federal Funds Purchased Securities Sold Under Agreements to Repurchase (In thousands) 2017 Outstanding at end of year $ 30,000 $ 32,169 Maximum outstanding at any month-end 100,000 67,249 Average balance for the year 22,742 58,872 Weighted average rate at end of year 1.50 % 0.09 % Weighted average rate paid for the year 1.19 % 0.09 % 2016 Outstanding at end of year $ 80,000 $ 59,624 Maximum outstanding at any month-end 180,000 77,466 Average balance for the year 29,542 66,282 Weighted average rate at end of year 0.75 % 0.05 % Weighted average rate paid for the year 0.54 % 0.05 % 2015 Outstanding at end of year $ — $ 58,215 Maximum outstanding at any month-end 102,000 75,313 Average balance for the year 10,008 64,320 Weighted average rate at end of year — % 0.05 % Weighted average rate paid for the year 0.31 % 0.05 %

Federal Home Loan Bank Borrow45

Federal Home Loan Bank Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
FEDERAL HOME LOAN BANK BORROWINGS [Abstract]
Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block]	A summary of borrowings from the FHLBs is as follows: December 31, 2017 Amount Weighted Average Rate (In thousands) Within 1 year $ 529,720 1.55 % Over 1 to 2 years 59,018 1.45 % Over 2 to 3 years 54,365 2.89 % Over 3 to 4 years 37,045 2.01 % Over 4 to 5 years 3,985 1.93 % Over 5 years 9,548 2.57 % Total $ 693,681 1.69 %

Junior Subordinated Debentures

Junior Subordinated Debentures (Tables)	12 Months Ended
	Dec. 31, 2017
JUNIOR SUBORDINATED DEBENTURES [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	The schedule below presents the detail of the Company’s junior subordinated debentures: December 31, 2017 2016 (In thousands) Boston Private Capital Trust II Junior Subordinated Debentures $ 103,093 $ 103,093 Boston Private Capital Trust I Junior Subordinated Debentures 3,270 3,270 Total $ 106,363 $ 106,363

Noncontrolling Interests (Table

Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2017
NONCONTROLLING INTERESTS [Abstract]
Redeemable Noncontrolling Interest [Table Text Block]	The following table presents, by affiliate, the noncontrolling interests included as redeemable noncontrolling interests and noncontrolling interests in mezzanine and permanent equity, respectively, at the periods indicated: December 31, 2017 December 31, 2016 (In thousands) Anchor $ 9,761 $ 10,934 BOS 8,057 6,782 DGHM (1) 4,829 3,417 Total $ 22,647 $ 21,133 Redeemable noncontrolling interests $ 17,461 $ 16,972 Noncontrolling interests $ 5,186 $ 4,161 _____________ (1) Only includes redeemable noncontrolling interests.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Table Text Block]	The following tables present an analysis of the Company’s redeemable noncontrolling interests for the periods indicated: Year ended December 31, 2017 December 31, 2016 December 31, 2015 Redeemable noncontrolling interests Noncontrolling interests Redeemable noncontrolling interests Noncontrolling interests Redeemable noncontrolling interests Noncontrolling interests (In thousands) Noncontrolling interests at beginning of period $ 16,972 $ 4,161 $ 18,088 $ 3,393 $ 20,905 $ 386 Net income attributable to noncontrolling interests 3,354 1,114 3,204 953 3,575 832 Distributions (3,277 ) (1,083 ) (3,112 ) (942 ) (4,189 ) (422 ) Purchases/ (sales) of ownership interests 235 85 (765 ) (134 ) (1,666 ) 419 Transfers of ownership interests from mezzanine to permanent equity — — — — (1,652 ) 1,652 Amortization of equity compensation 413 935 449 747 — 472 Adjustments to fair value (236 ) (26 ) (892 ) 144 1,115 54 Noncontrolling interests at end of period $ 17,461 $ 5,186 $ 16,972 $ 4,161 $ 18,088 $ 3,393

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Stock by Class [Table Text Block]	The following table summarizes the terms of the TARP warrant agreement outstanding at December 31, 2017 : Name of warrants Number of warrants Original warrant share number Current warrant share number (2) Original exercise price of warrants Current exercise price of warrants (2) Date issued Expiration date TARP Warrants (1) 1,692,755 1.00 1.14 $8.000 $7.011 11/21/2008 11/21/2018 ___________________ (1) The TARP warrants, while initially issued to the Treasury, were purchased from the Treasury by unrelated third parties at a market rate. (2) Per the terms of the TARP warrant agreement, the exercise price and number of shares issuable upon exercise may be adjusted ratably for dividends paid on the Company’s common stock that exceed the dividend rate at the time the warrants were issued, at which time the Company paid quarterly dividends of $0.01 per share. The current warrant share number and current exercise price of the warrant reflect the warrant as adjusted for common stock dividends through February 2, 2018, the latest dividend record date prior to the filing of this Annual Report.
Comprehensive Income (Loss) [Table Text Block]	The following table presents the Company’s comprehensive income/ (loss) and related tax effect for the years ended December 31, 2017 , 2016 , and 2015 : 2017 2016 2015 Pre- tax Tax effect Net of Tax Pre- Tax Net of Pre- Tax Net of (In thousands) Unrealized gain/ (loss) on securities available-for-sale Net gains/ (losses) arising during period $ 7,782 $ 3,063 $ 4,719 $ (18,913 ) $ (7,555 ) $ (11,358 ) $ (2,494 ) $ (1,145 ) $ (1,349 ) Less: Adjustment for realized gains/ (losses), net 376 154 222 521 190 331 236 97 139 Net change 7,406 2,909 4,497 (19,434 ) (7,745 ) (11,689 ) (2,730 ) (1,242 ) (1,488 ) Unrealized gain/ (loss) on cash flow hedges Net gains/ (losses) arising during period 325 135 190 (793 ) (332 ) (461 ) (2,642 ) (1,088 ) (1,554 ) Add: scheduled reclass and other 1,179 491 688 1,666 687 979 4,052 1,698 2,354 Net change 1,504 626 878 873 355 518 1,410 610 800 Unrealized gain/ (loss) on other Net gains/ (losses) arising during period 84 34 50 200 77 123 (193 ) (78 ) (115 ) Net change 84 34 50 200 77 123 (193 ) (78 ) (115 ) Total other comprehensive income/ (loss) 8,994 3,569 5,425 (18,361 ) (7,313 ) (11,048 ) (1,513 ) (710 ) (803 ) Net income attributable to the Company (1) 86,787 46,196 40,591 102,591 30,963 71,628 95,317 30,392 64,925 Total comprehensive income $ 95,781 $ 49,765 $ 46,016 $ 84,230 $ 23,650 $ 60,580 $ 93,804 $ 29,682 $ 64,122 ___________________ (1) Pre-tax net income attributable to the Company is calculated as income before income taxes, plus net income from discontinued operations, less net income attributable to noncontrolling interests.
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	The following table presents a summary of the amounts reclassified from accumulated other comprehensive income/ (loss) for the years ended December 31, 2017 , 2016 , and 2015 : Description of component of accumulated other comprehensive income/ (loss) Year ended December 31, Affected line item in Statement of Operations 2017 2016 2015 (In thousands) Adjustment for realized gains/(losses) on securities available-for-sale, net: Pre-tax $ 376 $ 521 $ 236 Gain/ (loss) on sale of investments, net Tax expense/ (benefit) 154 190 97 Income tax expense Net $ 222 $ 331 $ 139 Net income attributable to the Company Net realized gain/ (loss) on cash flow hedges: Hedge related to junior subordinated debentures: Pre-tax $ — $ — $ 1,879 Interest expense on junior subordinated debentures Tax expense/ (benefit) — — 804 Income tax expense Net $ — $ — $ (1,075 ) Net income attributable to the Company Hedge related to deposits Pre-tax $ 1,179 $ 1,666 $ 2,173 Interest expense on deposits Tax expense/ (benefit) 491 687 894 Income tax expense Net $ (688 ) $ (979 ) $ (1,279 ) Net income attributable to the Company Total reclassifications for the period, net of tax $ (688 ) $ (979 ) $ (2,354 )
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table presents the after-tax changes in the components of the Company’s accumulated other comprehensive income/ (loss) for the years ended December 31, 2017 , 2016 , and 2015 : Components of accumulated other comprehensive income/ (loss) Unrealized gain/ (loss) on securities available-for-sale Unrealized gain/ (loss) on cash flow hedges Unrealized gain/ (loss) on other Accumulated other comprehensive income/ (loss) (In thousands) Balance at December 31, 2014 $ 1,983 $ (1,923 ) $ (757 ) $ (697 ) Other comprehensive income/ (loss) before reclassifications (1,349 ) (1,554 ) (115 ) (3,018 ) Amounts reclassified from other comprehensive income/ (loss) (139 ) 2,354 — 2,215 Other comprehensive income/ (loss), net (1,488 ) 800 (115 ) (803 ) Balance at December 31, 2015 495 (1,123 ) (872 ) (1,500 ) Other comprehensive income/ (loss) before reclassifications (11,358 ) (461 ) 123 (11,696 ) Amounts reclassified from other comprehensive income/ (loss) (331 ) 979 — 648 Other comprehensive income/ (loss), net (11,689 ) 518 123 (11,048 ) Balance at December 31, 2016 (11,194 ) (605 ) (749 ) (12,548 ) Other comprehensive income/ (loss) before reclassifications 4,719 190 50 4,959 Amounts reclassified from other comprehensive income/ (loss) (222 ) 688 — 466 Other comprehensive income/ (loss), net 4,497 878 50 5,425 Reclassification due to the adoption of ASU 2018-02 (1,443 ) 59 (151 ) (1,535 ) Balance at December 31, 2017 $ (8,140 ) $ 332 $ (850 ) $ (8,658 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block]	The following tables present a reconciliation of the components of basic and diluted EPS computations for the three years ended December 31: For the year ended December 31, 2017 2016 2015 (In thousands, except share and per share data) Basic earnings per share - Numerator: Net income from continuing operations $ 40,189 $ 70,244 $ 62,921 Less: Net income attributable to noncontrolling interests 4,468 4,157 4,407 Net income from continuing operations attributable to the Company 35,721 66,087 58,514 Decrease/ (increase) in noncontrolling interests’ redemption values (1) (1,412 ) (588 ) 464 Dividends on preferred stock (3,475 ) (3,475 ) (3,475 ) Total adjustments to income attributable to common shareholders (4,887 ) (4,063 ) (3,011 ) Net income from continuing operations attributable to common shareholders, treasury stock method (2) 30,834 62,024 55,503 Net income from discontinued operations (2) 4,870 5,541 6,411 Net income attributable to common shareholders, treasury stock method (2) $ 35,704 $ 67,565 $ 61,914 Basic earnings per share - Denominator: Weighted average basic common shares outstanding 82,430,633 81,264,273 80,885,253 Per share data - Basic earnings per share from: Continuing operations $ 0.37 $ 0.76 $ 0.69 Discontinued operations $ 0.06 $ 0.07 $ 0.08 Total attributable to common shareholders $ 0.43 $ 0.83 $ 0.77 For the year ended December 31, 2017 2016 2015 (In thousands, except share and per share data) Diluted earnings per share - Numerator: Net income from continuing operations attributable to common shareholders, after assumed dilution (2) $ 30,834 $ 62,024 $ 55,503 Net income from discontinued operations 4,870 5,541 6,411 Net income attributable to common shareholders, after assumed dilution $ 35,704 $ 67,565 $ 61,914 Diluted earnings per share - Denominator: Weighted average basic common shares outstanding 82,430,633 81,264,273 80,885,253 Dilutive effect of: Stock options, performance-based and time-based restricted stock, and performance-based and time-based restricted stock units, and other dilutive securities (2), (3) 1,313,953 1,002,153 1,301,448 Warrants to purchase common stock (3) 1,057,979 942,700 1,206,389 Dilutive common shares 2,371,932 1,944,853 2,507,837 Weighted average diluted common shares outstanding (2), (3) 84,802,565 83,209,126 83,393,090 Per share data - Diluted earnings per share from: Continuing operations $ 0.36 $ 0.74 $ 0.66 Discontinued operations $ 0.06 $ 0.07 $ 0.08 Total attributable to common shareholders $ 0.42 $ 0.81 $ 0.74 Dividends per share declared and paid on common stock $ 0.44 $ 0.40 $ 0.36 _____________________ (1) See Part II. Item 8. “Financial Statements and Supplementary Data - Note 14: Noncontrolling Interests” for a description of the redemption values related to the redeemable noncontrolling interests. In accordance with ASC 480, Distinguishing Liabilities from Equity (“ASC 480”), an increase in redemption values from period to period reduces income attributable to common shareholders. Decreases in redemption value from period to period increase income attributable to common shareholders, but only to the extent that the cumulative change in redemption value remains a cumulative increase since adoption of this standard in the first quarter of 2009. (2) The Company presents its EPS based on the treasury stock method. The Company reverted to the treasury stock presentation from the two-class presentation due to the immaterial number of participating shares outstanding as of March 31, 2016. There is no difference between the calculation of EPS based on the treasury stock method and the calculation of EPS based on the two-class method for the year ended December 31, 2017. If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2016. Net income attributable to common shareholders would have been reduced by an additional $4 thousand , for the year ended December 31, 2016. The allocation of net income to participating securities would have been $8 thousand for the year ended December 31, 2016, reducing net income attributable to common shareholders by a total of $12 thousand for the same period. Basic EPS would not change. Weighted average diluted shared outstanding would have been reduced by 7,185 shares for the year ended December 31, 2016. Diluted EPS would not change. If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2015. Net income attributable to common shareholders would have been reduced by an additional $90 thousand for the year ended December 31, 2015, and the allocation of net income to participating securities would have been $92 thousand for the same period, reducing net income attributable to common shareholders by a total of $182 thousand , for the same period. Total basic EPS and basic EPS from continuing operations would each decrease by $0.01 per share for the year ended December 31, 2015. Weighted average diluted shares outstanding would have been reduced by 167,937 shares for the same period. Diluted EPS would not change. (3) The diluted EPS computations for the years ended December 31, 2017 , 2016 , and 2015 do not assume the conversion, exercise or contingent issuance of the following shares for the following periods because the result would have been antidilutive for the periods indicated. As a result of the anti-dilution, the potential common shares excluded from the diluted EPS computation are as follows: For the year ended December 31, 2017 2016 2015 Shares excluded due to anti-dilution (treasury stock method): (In thousands) Potential common shares from: Convertible trust preferred securities (a) 1 1 1 Total shares excluded due to anti-dilution 1 1 1 For the year ended December 31, 2017 2016 2015 Shares excluded due to exercise price exceeding the average market price of common shares during the period (total outstanding): (In thousands) Potential common shares from: Options, restricted stock, or other dilutive securities (b) 67 270 548 Total shares excluded due to exercise price exceeding the average market price of common shares during the period 67 270 548 (a) If the effect of the conversion of the trust preferred securities would have been dilutive, an immaterial amount of interest expense, net of tax, related to the convertible trust preferred securities would have been added back to net income attributable to common shareholders for the diluted EPS computation for the years presented. (b) Options to purchase shares of common stock, non-participating performance- and certain time-based restricted stock, and other dilutive securities that were outstanding at period ends were not included in the computation of diluted EPS or in the above anti-dilution table because their exercise or conversion prices were greater than the average market price of the common shares during the respective periods.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The components of income tax expense for continuing operations for the years ended December 31, 2017 , 2016 , and 2015 are as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Current expense: Federal $ 17,176 $ 20,237 $ 25,631 State 6,509 7,778 9,183 Total current expense 23,685 28,015 34,814 Deferred expense/(benefit): Federal 19,820 1,976 (3,185 ) State 2,691 972 (1,237 ) Total deferred expense/(benefit) 22,511 2,948 (4,422 ) Income tax expense $ 46,196 $ 30,963 $ 30,392
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Reconciliations between the Federal statutory income tax rate of 35% to the effective income tax rate for the years ended December 31, 2017 , 2016 , and 2015 are as follows: Year Ended December 31, 2017 2016 2015 Statutory Federal income tax rate 35.0 % 35.0 % 35.0 % Increase/ (decrease) resulting from: Re-measurement of deferred tax assets and liabilities 13.7 % — % — % Nondeductible goodwill 10.1 % — % — % Tax-exempt interest, net (10.3 )% (7.5 )% (7.1 )% State and local income tax, net of Federal tax benefit 6.9 % 5.6 % 5.5 % Tax credits (3.1 )% (2.2 )% (1.9 )% Investments in affordable housing projects 2.2 % 0.9 % 0.9 % Noncontrolling interests (1.5 )% (1.4 )% (1.6 )% Out-of-period adjustment — % — % 1.3 % Other, net 0.5 % 0.2 % 0.5 % Effective income tax rate 53.5 % 30.6 % 32.6 %
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The components of gross deferred tax assets and gross deferred tax liabilities at December 31, 2017 and 2016 are as follows: December 31, 2017 2016 (In thousands) Gross deferred tax assets: Allowance for loan and OREO losses $ 22,782 $ 35,545 Interest on nonaccrual loans 295 548 Stock compensation 3,156 6,079 Deferred and accrued compensation 11,822 19,801 Contingent payments 1,236 1,868 Unrealized loss on investments 3,345 8,264 Other 1,437 905 Gross deferred tax assets 44,073 73,010 Total deferred tax assets 44,073 73,010 Gross deferred tax liabilities: Deferred income on repurchase of debt 832 2,692 Goodwill and acquired intangible assets 12,246 12,929 Fixed assets 991 67 Prepaid expenses 347 611 Other 626 1,251 Total gross deferred tax liabilities 15,042 17,550 Net deferred tax asset $ 29,031 $ 55,460
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]	A reconciliation of the beginning and ending gross amount of unrecognized tax benefits under the provisions of ASC 740-10 is as follows: 2017 2016 2015 (In thousands) Balance at January 1 $ 974 $ 1,022 $ 1,067 Additions based on tax positions related to the current year 183 160 163 Additions based on tax positions taken in prior years 227 — — Decreases based on the expiration of statute of limitations (359 ) (208 ) (208 ) Balance at December 31 $ 1,025 $ 974 $ 1,022

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]	Share-based payments recorded in salaries and benefits expense are as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Stock option and ESPP expense $ 480 $ 437 $ 518 Nonvested share expense 7,794 6,293 5,723 Subtotal 8,274 6,730 6,241 Tax benefit 3,188 2,574 2,367 Stock-based compensation expense, net of tax benefit $ 5,086 $ 4,156 $ 3,874
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation, Stock Options, Activity [Table Text Block]	A summary of option activity under the 2009 Plan for the year ended December 31, 2017 is as follows: Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term in Years Aggregate Intrinsic Value (in 000’s) Outstanding at December 31, 2016 656,400 $ 13.11 Granted — $ — Exercised 109,400 $ 8.21 Forfeited 12,798 $ 28.85 Expired 115,547 $ 29.73 Outstanding at December 31, 2017 418,655 $ 9.32 1.81 years $ 2,795.0 Exercisable at December 31, 2017 418,655 $ 9.32 1.81 years $ 2,795.0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation, Stock Options, Activity [Table Text Block]	A summary of the Company’s nonvested shares as of December 31, 2017 and changes during the year ended December 31, 2017 , including shares under both the 2009 Plan and the Inducement Plan, is as follows: Shares Weighted- Average Grant-Date Fair Value Nonvested at December 31, 2016 1,993,628 $ 12.16 Granted 485,263 $ 15.55 Vested 652,193 $ 12.28 Forfeited 100,789 $ 13.35 Nonvested at December 31, 2017 1,725,909 $ 13.03

Other Operating Expense (Tables

Other Operating Expense (Tables)	12 Months Ended
	Dec. 31, 2017
OTHER OPERATING EXPENSE [Abstract]
Schedule of Other Operating Cost and Expense, by Component [Table Text Block]	Major components of other operating expense are as follows: Year Ended December 31, 2017 2016 2015 (In thousands) Employee travel and meals $ 3,910 $ 3,309 $ 2,874 Insurance 3,286 3,396 3,518 Other banking expenses 1,541 1,035 1,788 Publications and dues 1,028 984 870 Postage, express mail, and courier 974 967 1,007 Forms and supplies 890 836 1,241 OREO expenses 4 227 197 Provision/ (credit) for off-balance sheet loan commitments (24 ) (367 ) (271 ) Other 2,960 3,050 3,337 Total $ 14,569 $ 13,437 $ 14,561

Reportable Segments (Tables)

Reportable Segments (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Reconciliation of Reportable Segment Items The following tables present a reconciliation of the revenues, profits, assets, and other significant items of reportable segments as of and for the year ended December 31, 2017 , 2016 , and 2015 . Interest expense on junior subordinated debentures is reported at the Holding Company. Year ended December 31, 2017 2016 2015 Private Banking (In thousands) Net interest income $ 227,280 $ 202,702 $ 189,501 Fees and other income 10,856 18,947 11,352 Total revenues 238,136 221,649 200,853 Provision/ (credit) for loan losses (7,669 ) (6,935 ) (1,555 ) Operating expense 149,008 125,116 116,575 Income before income taxes 96,797 103,468 85,833 Income tax expense (1) 43,356 33,120 27,844 Net income from continuing operations 53,441 70,348 57,989 Net income attributable to the Company $ 53,441 $ 70,348 $ 57,989 Assets $ 8,177,304 $ 7,816,671 $ 7,361,202 Amortization of intangibles $ — $ — $ 341 Depreciation $ 5,639 $ 4,477 $ 4,599 Year ended December 31, 2017 2016 2015 Wealth Management and Trust (In thousands) Fees and other income $ 45,813 $ 44,401 $ 53,336 Operating expense (2) 49,287 64,844 54,474 Income/ (loss) before income taxes (3,474 ) (20,443 ) (1,138 ) Income tax expense / (benefit) (1) (509 ) (8,279 ) (350 ) Net income/ (loss) from continuing operations (2,965 ) (12,164 ) (788 ) Net income/ (loss) attributable to the Company $ (2,965 ) $ (12,164 ) $ (788 ) Assets $ 74,128 $ 80,501 $ 80,088 Amortization of intangibles $ 2,882 $ 2,962 $ 2,428 Depreciation $ 1,331 $ 1,145 $ 772 Year ended December 31, 2017 2016 2015 Investment Management (In thousands) Net interest income $ 21 $ 16 $ 22 Fees and other income 45,551 44,443 45,687 Total revenues 45,572 44,459 45,709 Operating expense (3) 59,032 32,863 33,690 Income/ (loss) before income taxes (13,460 ) 11,596 12,019 Income tax expense (1) 3,811 3,789 3,956 Net income/ (loss) from continuing operations (17,271 ) 7,807 8,063 Noncontrolling interests 1,973 2,077 2,265 Net income/ (loss) attributable to the Company $ (19,244 ) $ 5,730 $ 5,798 Assets $ 66,614 $ 92,692 $ 92,642 Amortization of intangibles $ 2,524 $ 2,601 $ 2,956 Depreciation $ 248 $ 284 $ 286 Year ended December 31, 2017 2016 2015 Wealth Advisory (In thousands) Net interest income $ 124 $ 16 $ 6 Fees and other income 52,636 50,686 50,558 Total revenues 52,760 50,702 50,564 Operating expense 35,753 34,791 35,379 Income before income taxes 17,007 15,911 15,185 Income tax expense (1) 6,418 6,084 5,819 Net income from continuing operations 10,589 9,827 9,366 Noncontrolling interests 2,495 2,080 2,138 Net income attributable to the Company $ 8,094 $ 7,747 $ 7,228 Assets $ 77,747 $ 79,887 $ 79,543 Amortization of intangibles $ 195 $ 719 $ 986 Depreciation $ 888 $ 878 $ 864 Year ended December 31, 2017 2016 2015 Holding Company and Eliminations (In thousands) Net interest income $ (2,739 ) $ (2,296 ) $ (3,759 ) Fees and other income (4) (890 ) 310 236 Total revenues (3,629 ) (1,986 ) (3,523 ) Operating expense 6,856 7,339 15,063 Income/ (loss) before income taxes (10,485 ) (9,325 ) (18,586 ) Income tax expense/(benefit) (1) (6,880 ) (3,751 ) (6,877 ) Net income/(loss) from continuing operations (3,605 ) (5,574 ) (11,709 ) Noncontrolling interests — — 4 Discontinued operations (5) 4,870 5,541 6,411 Net income/(loss) attributable to the Company $ 1,265 $ (33 ) $ (5,302 ) Assets (including eliminations) $ (84,049 ) $ (99,277 ) $ (70,967 ) Depreciation $ — $ 54 $ 69 Year ended December 31, 2017 2016 2015 Total Company (In thousands) Net interest income $ 224,686 $ 200,438 $ 185,770 Fees and other income 153,966 158,787 161,169 Total revenues 378,652 359,225 346,939 Provision/ (credit) for loan losses (7,669 ) (6,935 ) (1,555 ) Operating expense 299,936 264,953 255,181 Income before income taxes 86,385 101,207 93,313 Income tax expense (1) 46,196 30,963 30,392 Net income from continuing operations 40,189 70,244 62,921 Noncontrolling interests 4,468 4,157 4,407 Discontinued operations (5) 4,870 5,541 6,411 Net income attributable to the Company $ 40,591 $ 71,628 $ 64,925 Assets $ 8,311,744 $ 7,970,474 $ 7,542,508 Amortization of intangibles $ 5,601 $ 6,282 $ 6,711 Depreciation $ 8,106 $ 6,838 $ 6,590 ___________________ (1) The Company’s effective tax rate for 2017 , 2016 , and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017 , 2016 , and 2015 . See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details. (2) Operating expense related to the Wealth Management and Trust segment includes restructuring expenses of $2.0 million , and $3.7 million for the years ending December 31, 2016 and 2015 respectively, and a goodwill impairment charge of $9.5 million for the year ended December 31, 2016. (3) Operating expense related to the Investment Management Segment includes a goodwill impairment charge of $24.9 million for the year ended December 31, 2017. (4) Fees and other income for the Holding Company includes a loss on the sale of $1.3 million for the year ended December 31, 2017 related to the classification of Anchor as held for sale. (5) The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017 , 2016 and 2015 of $4.9 million , $5.5 million , and $6.4 million , respectively.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following tables present the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31, 2017 and 2016 , aggregated by the level in the fair value hierarchy within which those measurements fall: As of December 31, 2017 Fair value measurements at reporting date using: Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) (In thousands) Assets: Available-for-sale securities U.S. government and agencies $ 34,299 $ 34,096 $ 203 $ — Government-sponsored entities 302,501 — 302,501 — Municipal bonds 303,058 — 303,058 — Mortgage-backed securities 509,676 — 509,676 — Other 20,794 20,794 — — Total available-for-sale securities 1,170,328 54,890 1,115,438 — Derivatives - interest rate customer swaps 18,575 — 18,575 — Derivatives - interest rate swaps 555 — 555 — Derivatives - risk participation agreements 1 — 1 — Derivatives - customer foreign exchange forward 2 — 2 — Other investments 7,062 7,062 — — Liabilities: Derivatives - interest rate customer swaps $ 18,953 $ — $ 18,953 $ — Derivatives - interest rate swaps 80 — 80 — Derivatives - risk participation agreements 108 — 108 — Derivatives - customer foreign exchange forward 2 — 2 — Other liabilities 7,062 7,062 — — As of December 31, 2016 Fair value measurements at reporting date using: Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) (In thousands) Assets: Available-for-sale securities: U.S. government and agencies $ 39,936 $ 39,293 $ 643 $ — Government-sponsored entities 336,664 — 336,664 — Municipal bonds 293,397 — 293,397 — Mortgage-backed securities 570,327 — 570,327 — Other 23,808 23,808 — — Total available-for-sale securities 1,264,132 63,101 1,201,031 — Derivatives - interest rate customer swaps 17,032 — 17,032 — Derivatives - risk participation agreements 15 — 15 — Other investments 6,110 6,110 — — Liabilities: Derivatives - interest rate customer swaps $ 16,560 $ — $ 16,560 $ — Derivatives - interest rate swaps 1,040 — 1,040 — Derivatives - risk participation agreements 6 — 6 — Other liabilities 6,110 6,110 — —
Fair Value Measurements, Nonrecurring [Table Text Block]	The following tables present the Company’s assets and liabilities measured at fair value on a non-recurring basis during the periods ended December 31, 2017 and 2016 , respectively, aggregated by the level in the fair value hierarchy within which those measurements fall: As of December 31, 2017 Fair value measurements at reporting date using: Gain (losses) from fair value changes Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Year ended December 31, 2017 (In thousands) Assets: Impaired loans (1) $ 1,778 $ — $ — $ 1,778 $ (465 ) Goodwill (2) 42,054 — — 42,054 (24,901 ) $ 43,832 $ — $ — $ 43,832 $ (25,366 ) ___________________ (1) Collateral-dependent impaired loans held as of December 31, 2017 that had write-downs in fair value or whose specific reserve changed during 2017. (2) Goodwill balance at Anchor as of December 31, 2017 that had write-downs in fair value during 2017. The goodwill balance related to Anchor is recorded in other assets held for sale as of December 31, 2017 . See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for further detail. As of December 31, 2016 Fair value measurements at reporting date using: Gain (losses) from fair value changes Quoted prices in Significant Significant Year ended December 31, 2016 (In thousands) Assets: Impaired loans (1) $ 3,074 $ — $ — $ 3,074 $ (428 ) OREO (2) 1,690 — — 1,690 (110 ) Goodwill (3) 34,777 — — 34,777 (9,528 ) $ 39,541 $ — $ — $ 39,541 $ (10,066 ) ___________________ (1) Collateral-dependent impaired loans held as of December 31, 2016 that had write-downs in fair value or whose specific reserve changed during 2016 (2) OREO held as of December 31, 2016 that had write-downs in fair value during 2016. (3) Goodwill balance at Boston Private Wealth as of December 31, 2016 that had write-downs in fair value during 2016. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for further detail.
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block]	The following tables present additional quantitative information about assets measured at fair value on a non-recurring basis for which the Company has utilized Level 3 inputs to determine fair value: As of December 31, 2017 Fair Valuation Unobservable Range of Weighted (In thousands) Impaired Loans $ 1,778 Appraisals of Collateral Discount for costs to sell 0% - 7% 5% Appraisal adjustments 0% - 20% 14% See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for additional quantitative information about the 2017 goodwill impairment charges at Anchor. As of December 31, 2016 Fair Valuation Unobservable Range of Weighted (In thousands) Impaired Loans $ 3,074 Appraisals of Collateral Discount for costs to sell 5% - 7% 6% Appraisal adjustments 0% - 20% 13% OREO $ 1,690 Appraisals of Collateral Discount for costs to sell 6% 6% Appraisal adjustments 18% 18%
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following tables present the carrying values and fair values of the Company’s financial instruments that are not measured at fair value on a recurring basis (other than certain loans, as noted below): As of December 31, 2017 Book Value Fair Value Quoted prices Significant Significant (In thousands) FINANCIAL ASSETS: Cash and cash equivalents $ 120,541 $ 120,541 $ 120,541 $ — $ — Investment securities held-to-maturity 74,576 73,781 — 73,781 — Loans held for sale 4,697 4,737 — 4,737 — Loans, net 6,430,286 6,388,297 — — 6,388,297 Other financial assets 93,449 93,449 — 93,449 — FINANCIAL LIABILITIES: Deposits 6,510,246 6,509,197 — 6,509,197 — Securities sold under agreements to repurchase 32,169 32,169 — 32,169 — Federal funds purchased 30,000 30,000 — 30,000 — Federal Home Loan Bank borrowings 693,681 692,402 — 692,402 — Junior subordinated debentures 106,363 96,363 — — 96,363 Other financial liabilities 2,224 2,224 — 2,224 — As of December 31, 2016 Book Value Fair Value Quoted prices Significant Significant (In thousands) FINANCIAL ASSETS: Cash and cash equivalents $ 106,557 $ 106,557 $ 106,557 $ — $ — Investment securities held-to-maturity 93,079 92,604 — 92,604 — Loans held for sale 3,464 3,428 — 3,428 — Loans, net 6,036,277 6,021,611 — — 6,021,611 Other financial assets 77,956 77,956 — 77,956 — FINANCIAL LIABILITIES: Deposits 6,085,146 6,084,765 — 6,084,765 — Securities sold under agreements to repurchase 59,624 59,624 — 59,624 — Federal funds purchased 80,000 80,000 — 80,000 — Federal Home Loan Bank borrowings 734,205 734,941 — 734,941 — Junior subordinated debentures 106,363 96,363 — — 96,363 Other financial liabilities 1,942 1,942 — 1,942 —

Financial Instruments With Of55

Financial Instruments With Off-Balance Sheet Risk (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block]	Financial instruments with off-balance sheet risk are summarized as follows: December 31, 2017 2016 (In thousands) Commitments to originate loans Variable rate $ 56,410 $ 103,189 Fixed rate 79,784 65,563 Total commitments to originate new loans $ 136,194 $ 168,752 Unadvanced portion of loans and unused lines of credit $ 1,327,140 $ 1,280,648 Standby letters of credit $ 46,291 $ 38,391 Forward commitments to sell loans $ 16,886 $ 9,663

Boston Private Financial Hold56

Boston Private Financial Holdings, Inc. (Parent Company Only) (Tables)	12 Months Ended
	Dec. 31, 2017
BOSTON PRIVATE FINANCIAL HOLDINGS, INC. (PARENT COMPANY ONLY) [Abstract]
Schedule of Condensed Balance Sheet [Table Text Block]	CONDENSED BALANCE SHEETS December 31, 2017 December 31, 2016 (In thousands) Assets: Cash and cash equivalents $ 66,361 $ 54,694 Investment in wholly-owned and majority-owned subsidiaries: Bank 731,907 694,517 Non-banks 110,764 137,262 Investment in partnerships and trusts 6,340 6,340 Other assets 11,046 17,131 Total assets $ 926,418 $ 909,944 Liabilities: Junior subordinated debentures $ 106,363 $ 106,363 Deferred income taxes 5,322 8,638 Other liabilities 11,328 9,490 Total liabilities 123,013 124,491 Redeemable Noncontrolling Interests (1) 22,647 21,133 Total Shareholders’ Equity 780,758 764,320 Total liabilities, redeemable noncontrolling interests and shareholders’ equity $ 926,418 $ 909,944 ___________________ (1) Includes noncontrolling interests and the maximum redemption value of redeemable noncontrolling interests.
Schedule of Condensed Income Statement [Table Text Block]	CONDENSED STATEMENTS OF OPERATIONS Year ended December 31, 2017 2016 2015 (In thousands) Income: Interest income $ 180 $ 130 $ 116 Dividends from subsidiaries: Bank 25,200 22,700 22,700 Non-banks 24,116 24,044 28,789 Other income (1,071 ) 310 236 Total income 48,425 47,184 51,841 Operating Expense: Salaries and employee benefits 4,061 4,620 10,320 Professional fees 1,369 1,337 2,007 Interest expense 2,919 2,427 3,875 Other expenses 1,424 1,381 2,740 Total operating expense 9,773 9,765 18,942 Income before income taxes 38,652 37,419 32,899 Income tax benefit (6,880 ) (3,751 ) (6,877 ) Net income from discontinued operations 4,870 5,541 6,411 Income before equity in undistributed earnings of subsidiaries 50,402 46,711 46,187 Equity / (loss) in undistributed earnings of subsidiaries (9,811 ) 24,917 18,738 Net income attributable to the Company $ 40,591 $ 71,628 $ 64,925
Schedule of Condensed Cash Flow Statement [Table Text Block]	CONDENSED STATEMENTS OF CASH FLOWS Year ended December 31, 2017 2016 2015 (In thousands) Cash flows from operating activities: Net income attributable to the Company $ 40,591 $ 71,628 $ 64,925 Net income from discontinued operations 4,870 5,541 6,411 Net income from continuing operations 35,721 66,087 58,514 Adjustments to reconcile net income from continuing operations to net cash provided by/ (used in) operating activities: Equity in earnings/ (loss) of subsidiaries: Bank (50,476 ) (58,184 ) (57,201 ) Non-banks 11,150 (13,477 ) (13,026 ) Dividends from subsidiaries: Bank 25,200 22,700 22,700 Non-banks 24,116 24,044 28,789 Deferred income tax expense/ (benefit) (3,075 ) 10,000 (4,575 ) Depreciation and amortization 3,553 (738 ) 5,097 Net decrease/ (increase) in other operating activities 1,899 (16,633 ) 2,167 Net cash provided by/ (used in) operating activities of continuing operations 48,088 33,799 42,465 Net cash provided by/ (used in) operating activities of discontinued operations 4,870 5,541 6,411 Net cash provided by/ (used in) operating activities 52,958 39,340 48,876 Cash flows from investing activities: Cash paid for acquisitions, including deferred acquisition obligations 1,410 1,890 1,821 Capital investments in subsidiaries: Bank — — — Non-banks (54 ) (1,220 ) (1,723 ) Net cash (used in)/ provided by in other investing activities — 1 1 Net cash provided by/ (used in) investing activities 1,356 671 99 Cash flows from financing activities: Repurchase of common stock — (9,323 ) — Dividends paid to common shareholders (37,054 ) (33,110 ) (29,608 ) Dividends paid to preferred shareholders (3,475 ) (3,475 ) (3,475 ) Tax benefit/ (deficiency) from certain stock compensation awards — (620 ) (1,262 ) Proceeds from stock option exercises 882 1,725 1,206 Proceeds from issuance of common stock, net 2,740 7,786 160 Other equity adjustments (5,740 ) (3,685 ) (5,204 ) Net cash provided by/ (used in) financing activities (42,647 ) (40,702 ) (38,183 ) Net (decrease)/ increase in cash and cash equivalents 11,667 (691 ) 10,792 Cash and cash equivalents at beginning of year 54,694 55,385 44,593 Cash and cash equivalents at end of year $ 66,361 $ 54,694 $ 55,385

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
REGULATORY MATTERS [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	Actual For capital adequacy purposes (at least) To be well capitalized under prompt corrective action provisions (at least) Basel III minimum capital ratio with capital conservation buffer (1) Amount Ratio Amount Ratio Amount Ratio (In thousands) As of December 31, 2017 Common equity tier 1 risk-based capital Company $ 607,800 10.32 % $ 265,153 4.5 % n/a n/a 7.0 % Boston Private Bank 694,201 11.83 264,028 4.5 $ 381,373 6.5 % 7.0 Tier 1 risk-based capital Company 758,089 12.87 353,537 6.0 n/a n/a 8.5 Boston Private Bank 694,201 11.83 352,037 6.0 469,382 8.0 8.5 Total risk-based capital Company 832,182 14.12 471,383 8.0 n/a n/a 10.5 Boston Private Bank 767,576 13.08 469,382 8.0 586,728 10.0 10.5 Tier 1 leverage capital Company 758,089 9.34 324,725 4.0 n/a n/a 4.0 Boston Private Bank 694,201 8.63 321,920 4.0 402,400 5.0 4.0 As of December 31, 2016 Common equity tier 1 risk-based capital Company $ 571,663 10.00 % $ 257,222 4.5 % n/a n/a 7.0 % Boston Private Bank 661,991 11.64 256,030 4.5 $ 369,822 6.5% 7.0 Tier 1 risk-based capital Company 722,674 12.64 342,962 6.0 n/a n/a 8.5 Boston Private Bank 661,991 11.64 341,374 6.0 455,165 8.0 8.5 Total risk-based capital Company 794,584 13.90 457,283 8.0 n/a n/a 10.5 Boston Private Bank 733,214 12.89 455,165 8.0 568,956 10.0 10.5 Tier 1 leverage capital Company 722,674 9.42 306,848 4.0 n/a n/a 4.0 Boston Private Bank 661,991 8.70 304,510 4.0 380,637 5.0 4.0 ___________________ n/a = not applicable (1) Required capital ratios under the Basel III capital rules with the fully phased-in capital conservation buffer added to the minimum risk-based capital ratios. The fully phased-in ratios are effective for 2019, with lower requirements during the transition years 2016 through 2018.

Selected Quarterly Data (Unau58

Selected Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
SELECTED QUARTERLY DATA (UNAUDITED) [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	The following tables present selected quarterly financial data for 2017 and 2016 : 2017 (1) (In thousands, except per share data) Fourth Quarter Third Quarter Second Quarter First Quarter Revenues Net interest income $ 57,272 $ 56,627 $ 57,145 $ 53,642 Fees and other income 39,175 40,267 38,018 36,506 Total revenues 96,447 96,894 95,163 90,148 Provision/ (credit) for loan losses (942 ) (432 ) (6,114 ) (181 ) Operating expense 93,989 69,346 67,821 68,780 Income before income taxes 3,400 27,980 33,456 21,549 Income tax expense 21,391 8,289 9,963 6,553 Net income from discontinued operations 989 1,186 1,063 1,632 Less: Net income attributable to noncontrolling interests 1,278 1,074 1,150 966 Net income/ (loss) attributable to the Company $ (18,280 ) $ 19,803 $ 23,406 $ 15,662 Net earnings/ (loss) per share attributable to the Company’s common shareholders: Basic earnings/ (loss) per share (2) $ (0.24 ) $ 0.23 $ 0.28 $ 0.18 Diluted earnings/ (loss) per share (2) $ (0.24 ) $ 0.22 $ 0.27 $ 0.17 2016 (1) (In thousands, except per share data) Fourth Quarter Third Quarter Second Quarter First Quarter Revenues Net interest income $ 51,519 $ 49,871 $ 49,169 $ 49,879 Fees and other income 43,958 40,012 36,795 38,022 Total revenues 95,477 89,883 85,964 87,901 Provision/ (credit) for loan losses (1,128 ) (138 ) (2,535 ) (3,133 ) Operating expense 71,843 61,670 64,731 66,709 Income before income taxes 24,762 28,351 23,768 24,325 Income tax expense 7,247 8,652 7,626 7,438 Net income from discontinued operations 1,184 1,047 1,245 2,065 Less: Net income attributable to noncontrolling interests 1,147 1,110 989 911 Net income attributable to the Company $ 17,552 $ 19,636 $ 16,398 $ 18,041 Net earnings per share attributable to the Company’s common shareholders: Basic earnings per share (2) $ 0.19 $ 0.23 $ 0.19 $ 0.22 Diluted earnings per share (2) $ 0.19 $ 0.22 $ 0.18 $ 0.21 ___________________ (1) Due to rounding, the sum of the four quarters may not add to the year to date total. (2) Includes the effect of adjustments to net income attributable to the Company to arrive at net income attributable to common shareholders.

Basis of Presentation and Sum59

Basis of Presentation and Summary of Significant Accounting Policies Significant Accounting Policies Text (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 0
Cash Reserve Deposit Required and Made	3,600,000	$ 5,000,000
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	0	$ 0	$ 0
Effective tax rate reconciliation, share based compensation	300,000
Retained Earnings [Member]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 1,535,000

Restructuring (Details)

Restructuring (Details) - USD ($)	3 Months Ended			12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				$ 0	$ 2,017,000	$ 3,724,000
Restructuring and Related Cost, Cost Incurred to Date				6,400,000
Restructuring Reserve			$ 739,000	337,000	1,977,000	3,305,000
Restructuring Reserve, Settled with Cash				(1,640,000)	(3,345,000)	(1,158,000)
Restructuring and Related Cost, Expected Cost				0
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				0	2,017,000	3,434,000
Restructuring Reserve			739,000	337,000	1,977,000	3,305,000
Restructuring Reserve, Settled with Cash				(1,640,000)	(3,345,000)	(868,000)
Other Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost				0	0	290,000
Restructuring Reserve			0	0	0	0
Restructuring Reserve, Settled with Cash				$ 0	$ 0	(290,000)
Banyan Acquisition and WMT Management Restructuring Plan [Member] | Wealth Management and Trust Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 900,000	$ 1,100,000	$ 700,000			$ 3,700,000

Acquisitions, Asset Sales, an61

Acquisitions, Asset Sales, and Divestitures Asset Sales and Divestitures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, Impairment Loss	$ 24,901	$ 9,528	$ 0
Long Lived Assets Held-for-sale, Description		The rationale for the sale was to better position the Company’s resources within the Southern California market.
Disposal Group, Liabilities, Deposits Included in Sale		$ 104,000
Gain/ (loss) on sale of affiliates or offices	(1,264)	$ 2,862	$ 0
Anchor [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sales of Business, Affiliate and Productive Assets	32,000
Proceeds from Divestiture of Interest in Subsidiaries and Affiliates	15,000
Goodwill, Impairment Loss	24,900
Disposal Group, Including Discontinued Operation, Assets	58,800
Disposal Group, Including Discontinued Operation, Liabilities	3,200
Gain (Loss) on Sale of Properties, Applicable Income Taxes	$ 11,400
Long Lived Assets Held-for-sale, Description	The rationale for the sale is to focus the Company’s resources in businesses where we can offer holistic financial advice, along with integrated wealth management, trust, and private banking capabilities. This transaction will also generate additional capital for us to reinvest in a more focused Company.
Westfield Capital Management Company LLC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Nature of Activities Having Continuing Cash Flows after Disposal	12.5% share in Westfield’s revenues (up to an annual maximum of $11.6 million)
Discontinued Operation, Period of Continuing Cash Flows after Disposal	1 year

Acquisitions, Asset Sales, an62

Acquisitions, Asset Sales, and Divestitures Acquisitions (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill, Acquired During Period	$ 0	$ 0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 0	$ 0
2014 Acquisition of Banyan Partners LLC [Member]
Business Acquisition [Line Items]
Business Acquisition, Name of Acquired Entity				Banyan Partners, LLC
Business Acquisition, Effective Date of Acquisition				Oct. 2, 2014
Business Acquisition, Description of Acquired Entity				Banyan, a registered investment advisory firm headquartered in Palm Beach Gardens, Florida. At the time of acquisition, Banyan had approximately $4.3 billion in client assets and locations in New England; South Florida; Texas; California; Atlanta, Georgia; and Madison, Wisconsin.
Business Acquisition, Percentage of Voting Interests Acquired				100.00%
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares				1.7
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable				$ 21,000
Business Combination, Consideration Transferred				43,900
Business Combination, Contingent Consideration, Asset				5,000
Business Combination, Contingent Consideration, Liability				2,000
Payments to Acquire Businesses, Gross				66,900
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability			$ 2,000
Goodwill, Acquired During Period				41,900
Business Acquisition, Goodwill, Expected Tax Deductible Amount				39,900
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				$ 23,900
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				10 years
Business Combination, Reason for Business Combination				The rationale for the transaction was that by merging Banyan with the existing Boston Private Bank wealth management business, additional technical expertise and financial acumen would be generated. Banyan has been merged with the existing wealth management business from Boston Private Bank, and the combined company has been renamed Boston Private Wealth. As a wholly-owned subsidiary of the Bank, Boston Private Wealth will also operate as part of the Wealth Management and Trust segment along with the trust operations of the Bank. These operations are reported separately from the Private Banking operations of the Bank.

Investments Schedule of Availab

Investments Schedule of Available for sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017		Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 1,182,427		$ 1,283,161
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	5,072		4,635
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	17,171		23,664
Available-for-sale Securities	1,170,328		1,264,132
Held-to-maturity Securities	74,576		93,079
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0		1
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(795)		(476)
Held-to-maturity Securities, Fair Value	73,781		92,604
U.S. government and agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	35,132	[1]	40,704
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0		86
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	833		854
Available-for-sale Securities	34,299	[1]	39,936
Government-sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	305,101	[1]	337,865
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	22		1,058
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	2,622		2,259
Available-for-sale Securities	302,501	[1]	336,664
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	299,647	[1]	296,271
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	4,559		2,116
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,148		4,990
Available-for-sale Securities	303,058	[1]	293,397
Mortgage-backed securities (1)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	521,753	[2]	584,960	[3]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	491		928	[3]
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	12,568		15,561	[3]
Available-for-sale Securities	509,676	[2]	570,327	[3]
Held-to-maturity Securities	74,576	[2]	93,079	[3]
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0		1	[3]
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(795)		(476)	[3]
Held-to-maturity Securities, Fair Value	73,781	[2]	92,604	[3]
Other
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	20,794	[4]	23,361
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0		447
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0		0
Available-for-sale Securities	$ 20,794	[4]	$ 23,808
[1]	Certain securities are callable before their final maturity.
[2]	Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives.
[3]	All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.
[4]	Other securities consist of money market mutual funds and equity securities held by certain Wealth Advisory and Investment Management businesses.

Investments Maturities of Avail

Investments Maturities of Available for sale Securities by Type (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis		$ 1,182,427		$ 1,283,161
Available-for-sale Securities		$ 1,170,328		$ 1,264,132
Weighted Average Remaining Maturity, Available for Sale Securities		8 years 20 days		9 years 1 month 20 days
Available for Sale Securities Callable Before Maturity		$ 184,900		$ 140,400
U.S. government and agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	[1]	0
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	[1]	$ 0
Available for sale Securities, Maturities, Next Twelve Months, Weighted Average Yield	[1]	0.00%
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	[1]	$ 15,192
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	[1]	$ 15,105
Available for sale Securities, Maturities, Year Two Through Five, Weighted Average Yield	[1]	1.53%
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	[1]	$ 19,940
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	[1]	$ 19,194
Available for sale Securities, Maturities, Year Six Through Ten, Weighted Average Yield	[1]	1.73%
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	[1]	$ 0
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	[1]	$ 0
Available for sale Securities, Maturities, After Ten Years, Weighted Average Yield	[1]	0.00%
Available-for-sale Securities, Amortized Cost Basis		$ 35,132	[1]	40,704
Available-for-sale Securities		$ 34,299	[1]	39,936
Available for sale Securities, Weighted Average Yield	[1]	1.64%
Government-sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	[1]	$ 44,033
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	[1]	$ 43,967
Available for sale Securities, Maturities, Next Twelve Months, Weighted Average Yield	[1]	1.39%
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	[1]	$ 224,747
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	[1]	$ 223,315
Available for sale Securities, Maturities, Year Two Through Five, Weighted Average Yield	[1]	1.86%
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	[1]	$ 36,321
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	[1]	$ 35,219
Available for sale Securities, Maturities, Year Six Through Ten, Weighted Average Yield	[1]	2.05%
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	[1]	$ 0
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	[1]	$ 0
Available for sale Securities, Maturities, After Ten Years, Weighted Average Yield	[1]	0.00%
Available-for-sale Securities, Amortized Cost Basis		$ 305,101	[1]	337,865
Available-for-sale Securities		$ 302,501	[1]	336,664
Available for sale Securities, Weighted Average Yield	[1]	1.81%
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	[1]	$ 15,770
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	[1]	$ 15,756
Available for sale Securities, Maturities, Next Twelve Months, Weighted Average Yield	[1],[2]	1.85%
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	[1]	$ 57,178
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	[1]	$ 57,260
Available for sale Securities, Maturities, Year Two Through Five, Weighted Average Yield	[1],[2]	2.63%
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	[1]	$ 33,979
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	[1]	$ 34,719
Available for sale Securities, Maturities, Year Six Through Ten, Weighted Average Yield	[1],[2]	3.73%
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	[1]	$ 192,720
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	[1]	$ 195,323
Available for sale Securities, Maturities, After Ten Years, Weighted Average Yield	[1],[2]	4.07%
Available-for-sale Securities, Amortized Cost Basis		$ 299,647	[1]	296,271
Available-for-sale Securities		$ 303,058	[1]	293,397
Available for sale Securities, Weighted Average Yield	[1],[2]	3.64%
Mortgage-backed securities (1)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	[3]	$ 17
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	[3]	$ 17
Available for sale Securities, Maturities, Next Twelve Months, Weighted Average Yield	[3]	2.33%
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	[3]	$ 11,460
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	[3]	$ 11,407
Available for sale Securities, Maturities, Year Two Through Five, Weighted Average Yield	[3]	2.25%
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	[3]	$ 236,360
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	[3]	$ 229,770
Available for sale Securities, Maturities, Year Six Through Ten, Weighted Average Yield	[3]	2.18%
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	[3]	$ 273,916
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	[3]	$ 268,482
Available for sale Securities, Maturities, After Ten Years, Weighted Average Yield	[3]	2.10%
Available-for-sale Securities, Amortized Cost Basis		$ 521,753	[3]	584,960	[4]
Available-for-sale Securities		$ 509,676	[3]	570,327	[4]
Available for sale Securities, Weighted Average Yield	[3]	2.14%
Other
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	[5]	$ 20,794
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	[5]	$ 20,794
Available for sale Securities, Maturities, Next Twelve Months, Weighted Average Yield	[5]	0.00%
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	[5]	$ 0
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	[5]	$ 0
Available for sale Securities, Maturities, Year Two Through Five, Weighted Average Yield	[5]	0.00%
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	[5]	$ 0
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	[5]	$ 0
Available for sale Securities, Maturities, Year Six Through Ten, Weighted Average Yield	[5]	0.00%
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	[5]	$ 0
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	[5]	$ 0
Available for sale Securities, Maturities, After Ten Years, Weighted Average Yield	[5]	0.00%
Available-for-sale Securities, Amortized Cost Basis		$ 20,794	[5]	23,361
Available-for-sale Securities		$ 20,794	[5]	$ 23,808
Available for sale Securities, Weighted Average Yield	[5]	0.00%
[1]	Certain securities are callable before their final maturity.
[2]	Yields shown on a fully taxable equivalent (“FTE”) basis. The tax rate used in the table above was the tax rate in effect on December 31, 2017. The recent enactment of the Tax Act will reduce the rate applied in future periods, which will result in a lower FTE yield.
[3]	Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives.
[4]	All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.
[5]	Other securities consist of money market mutual funds and equity securities held by certain Wealth Advisory and Investment Management businesses.

Investments Maturities of Held

Investments Maturities of Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount		$ 57,854
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value		57,230
Held-to-maturity Securities		74,576		$ 93,079
Held-to-maturity Securities, Fair Value		$ 73,781		$ 92,604
Weighted Average Remaining Maturity, Held To Maturity Securities		11 years 10 months 25 days		12 years 11 months 10 days
Mortgage-backed securities (1)
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount	[1]	$ 0
Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value	[1]	$ 0
Held to maturity securities, Maturities, Next Twelve Months, Weighted Average Yield	[1]	0.00%
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	[1]	$ 0
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	[1]	$ 0
Held to maturity securities, Maturities, Year Two Through Five, Weighted Average Yield	[1]	0.00%
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	[1]	$ 16,722
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	[1]	$ 16,551
Held to maturity securities, Maturities, Year Six Through Ten, Weighted Average Yield	[1]	2.17%
Held to maturity Securities, Maturities, After Ten Years, Weighted Average Yield	[1]	2.30%
Held-to-maturity Securities		$ 74,576	[1]	$ 93,079	[2]
Held-to-maturity Securities, Fair Value		$ 73,781	[1]	$ 92,604	[2]
Held to maturity securities, Weighted average yield	[1]	2.27%
[1]	Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives.
[2]	All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.

Investments Realized Gain (Loss

Investments Realized Gain (Loss) on Securities Sold (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Sale of Available-for-sale Securities	$ 148,407	$ 50,049	$ 34,160
Available-for-sale Securities, Gross Realized Gains	519	522	272
Available-for-sale Securities, Gross Realized Losses	$ (143)	$ (1)	$ (36)

Investments Available for Sale

Investments Available for Sale Securities in Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2017USD ($)securities		Dec. 31, 2016USD ($)securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 378,406		$ 818,909
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2,463)		(22,042)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	495,297		44,907
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(14,708)		(1,622)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	873,703		863,816
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (17,171)		$ (23,664)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	208		230
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 59,218		$ 87,483
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	534		476
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	14,563		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	261		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	73,781		87,483
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 795		$ 476
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	16		15
U.S. government and agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 14,902		$ 19,094
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(79)		(838)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	19,397		643
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(754)		(16)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	34,299		19,737
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (833)		$ (854)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	6		4
Government-sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 220,275		$ 125,412
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,350)		(2,259)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	38,273		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,272)		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	258,548		125,412
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (2,622)		$ (2,259)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	36		18
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 46,112		$ 182,395
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(131)		(4,957)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	50,842		2,720
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,017)		(33)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	96,954		185,115
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (1,148)		$ (4,990)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	63		109
Mortgage-backed securities (1)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 97,117		$ 492,008
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(903)		(13,988)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	386,785		41,544
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(11,665)		(1,573)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	483,902	[1]	533,552
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (12,568)	[1]	$ (15,561)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	103		99
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 59,218		$ 87,483
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	534		476
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	14,563		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	261		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	73,781		87,483
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 795		$ 476
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | securities	16		15
[1]	All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.

Investments Investments in Any

Investments Investments in Any One Issuer Exceeding Ten Percent of Equity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 1,182,427	$ 1,283,161
Available-for-sale Securities	1,170,328	$ 1,264,132
Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Available-for-sale Securities, Amortized Cost Basis	876,373
Available-for-sale Securities	$ 861,205
Stockholders' Equity, Total [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	10.00%
Government National Mortgage Association | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 104,188
Available-for-sale Securities	101,941
Federal Home Loan Mortgage Corporation | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Available-for-sale Securities, Amortized Cost Basis	349,926
Available-for-sale Securities	342,374
Federal Home Loan Bank | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Available-for-sale Securities, Amortized Cost Basis	163,151
Available-for-sale Securities	161,747
Federal National Mortgage Association | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Available-for-sale Securities, Amortized Cost Basis	259,108
Available-for-sale Securities	$ 255,143

Investments Other investment di

Investments Other investment disclosures (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Cost-method Investments [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	$ 39.4	$ 34.2
Qualified Affordable Housing Project Investments, Commitment	$ 11.5	$ 11.3
Cost Method Investments, Additional Information	0	0
Income Tax Expense [Member]
Schedule of Cost-method Investments [Line Items]
Amortization Method Qualified Affordable Housing Project Investments, Amortization	$ 2.7	$ 1.6	$ 1.3
Affordable Housing Tax Credits and Other Tax Benefits, Amount	$ 2.2	$ 1.7	$ 1.3

Loans Receivable and Credit Q70

Loans Receivable and Credit Quality Loans by Portfolio Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 6,505,028	$ 6,114,354
Commercial and Industrial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	939,690	1,009,974
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	520,992	611,370
Commercial Tax Exempt [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	418,698	398,604
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,440,220	2,302,244
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	164,990	104,839
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,682,533	2,379,861
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	99,958	118,817
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 177,637	$ 198,619

Loans Receivable and Credit Q71

Loans Receivable and Credit Quality Nonaccrual Loans by Class of Financing Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 14,295	$ 17,315
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	748	572
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	748	572
Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,985	4,583
Construction Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	110	179
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	8,470	10,908
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,840	1,072
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 142	$ 1

Loans Receivable and Credit Q72

Loans Receivable and Credit Quality Loans by Past Due Status (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 25,048	$ 15,137
Financing Receivable, Recorded Investment, Nonaccrual Status	14,295	17,315
Financing Receivable, Recorded Investment, Current	6,465,685	6,081,902
Total loans	6,505,028	6,114,354
Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	11,752	1,619
Financing Receivable, Recorded Investment, Nonaccrual Status	748	572
Financing Receivable, Recorded Investment, Current	508,492	609,179
Total loans	520,992	611,370
Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Financing Receivable, Recorded Investment, Current	418,698	398,604
Total loans	418,698	398,604
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,043	3,096
Financing Receivable, Recorded Investment, Nonaccrual Status	1,985	4,583
Financing Receivable, Recorded Investment, Current	2,434,192	2,294,565
Total loans	2,440,220	2,302,244
Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	110	179
Financing Receivable, Recorded Investment, Current	164,880	104,660
Total loans	164,990	104,839
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	8,874	4,182
Financing Receivable, Recorded Investment, Nonaccrual Status	8,470	10,908
Financing Receivable, Recorded Investment, Current	2,665,189	2,364,771
Total loans	2,682,533	2,379,861
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	355	245
Financing Receivable, Recorded Investment, Nonaccrual Status	2,840	1,072
Financing Receivable, Recorded Investment, Current	96,763	117,500
Total loans	99,958	118,817
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	24	5,995
Financing Receivable, Recorded Investment, Nonaccrual Status	142	1
Financing Receivable, Recorded Investment, Current	177,471	192,623
Total loans	177,637	198,619
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	22,564	13,523
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	10,903	541
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,043	3,096
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	7,239	3,646
Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	355	245
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	24	5,995
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,484	1,614
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	849	1,078
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,635	536
Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivables, 1 to 29 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,340	5,126
Financing Receivables, 1 to 29 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	355	537
Financing Receivables, 1 to 29 Days Past Due [Member] | Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Financing Receivables, 1 to 29 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	163	2,311
Financing Receivables, 1 to 29 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	129
Financing Receivables, 1 to 29 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	805	2,148
Financing Receivables, 1 to 29 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Financing Receivables, 1 to 29 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	17	1
Financing Receivables, 30 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,368	2,201
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Financing Receivables, 30 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	835
Financing Receivables, 30 to 89 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	12
Financing Receivables, 30 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,172	1,274
Financing Receivables, 30 to 89 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	71	80
Financing Receivables, 30 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	125	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	9,587	9,988
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	393	35
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,822	1,437
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	110	38
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	4,493	7,486
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,769	992
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 0	$ 0

Loans Receivable and Credit Q73

Loans Receivable and Credit Quality Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 6,505,028	$ 6,114,354
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	520,992	611,370
Commercial Tax Exempt [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	418,698	398,604
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,440,220	2,302,244
Construction Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	164,990	104,839
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,682,533	2,379,861
Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	99,958	118,817
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	177,637	198,619
Performing Financial Instruments [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,350,207	5,995,833
Performing Financial Instruments [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	87,174	37,535
Performing Financial Instruments [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	53,352	63,671
Performing Financial Instruments [Member] | Commercial Loan [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	496,395	591,388
Performing Financial Instruments [Member] | Commercial Loan [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,898	10,133
Performing Financial Instruments [Member] | Commercial Loan [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	10,951	9,277
Performing Financial Instruments [Member] | Commercial Tax Exempt [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	413,139	388,544
Performing Financial Instruments [Member] | Commercial Tax Exempt [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,559	10,060
Performing Financial Instruments [Member] | Commercial Tax Exempt [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Performing Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,346,833	2,230,732
Performing Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	56,947	17,233
Performing Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	34,455	49,696
Performing Financial Instruments [Member] | Construction Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	146,514	101,254
Performing Financial Instruments [Member] | Construction Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,770	109
Performing Financial Instruments [Member] | Construction Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,596	3,297
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,672,714	2,367,554
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,349	1,399
Performing Financial Instruments [Member] | Home Equity Line of Credit [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	97,118	117,745
Performing Financial Instruments [Member] | Home Equity Line of Credit [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Performing Financial Instruments [Member] | Home Equity Line of Credit [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	177,494	198,616
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1	2
Nonperforming Financial Instruments [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,295	17,315
Nonperforming Financial Instruments [Member] | Commercial Loan [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	748	572
Nonperforming Financial Instruments [Member] | Commercial Tax Exempt [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Nonperforming Financial Instruments [Member] | Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,985	4,583
Nonperforming Financial Instruments [Member] | Construction Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	110	179
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,470	10,908
Nonperforming Financial Instruments [Member] | Home Equity Line of Credit [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,840	1,072
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 142	$ 1

Loans Receivable and Credit Q74

Loans Receivable and Credit Quality Impaired Loans With and Without Related Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$ 14,491	$ 14,594
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	17,288	20,815
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	15,311	22,323
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	2,036	1,540
Impaired Financing Receivable, with Related Allowance, Recorded Investment	8,086	11,436
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	8,640	11,865
Impaired Financing Receivable, Related Allowance	654	1,135
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	9,651	13,276
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	416	458
Impaired Financing Receivable, Recorded Investment	22,577	26,030
Impaired Financing Receivable, Unpaid Principal Balance	25,928	32,680
Impaired Financing Receivable, Average Recorded Investment	24,962	35,599
Impaired Financing Receivable, Interest Income, Cash Basis Method	2,452	1,998
Commercial Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,434	1,793
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,238	2,155
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,594	5,288
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	50	249
Impaired Financing Receivable, with Related Allowance, Recorded Investment	242	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	242	0
Impaired Financing Receivable, Related Allowance	58	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	156	31
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	4	1
Impaired Financing Receivable, Recorded Investment	1,676	1,793
Impaired Financing Receivable, Unpaid Principal Balance	2,480	2,155
Impaired Financing Receivable, Average Recorded Investment	1,750	5,319
Impaired Financing Receivable, Interest Income, Cash Basis Method	54	250
Commercial Tax Exempt [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,001	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	80	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, Related Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, Recorded Investment	0	0
Impaired Financing Receivable, Unpaid Principal Balance	0	0
Impaired Financing Receivable, Average Recorded Investment	1,001	0
Impaired Financing Receivable, Interest Income, Cash Basis Method	80	0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,832	4,488
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	3,453	9,647
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	3,098	8,520
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	1,546	1,032
Impaired Financing Receivable, with Related Allowance, Recorded Investment	6,855	7,115
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	7,284	7,544
Impaired Financing Receivable, Related Allowance	362	548
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	6,980	7,230
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	322	314
Impaired Financing Receivable, Recorded Investment	8,687	11,603
Impaired Financing Receivable, Unpaid Principal Balance	10,737	17,191
Impaired Financing Receivable, Average Recorded Investment	10,078	15,750
Impaired Financing Receivable, Interest Income, Cash Basis Method	1,868	1,346
Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	109	179
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	109	507
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	172	1,069
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	48
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, Related Allowance	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	507
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, Recorded Investment	109	179
Impaired Financing Receivable, Unpaid Principal Balance	109	507
Impaired Financing Receivable, Average Recorded Investment	172	1,576
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	48
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,337	8,134
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	9,709	8,506
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,033	7,446
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	360	211
Impaired Financing Receivable, with Related Allowance, Recorded Investment	828	4,284
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	828	4,284
Impaired Financing Receivable, Related Allowance	89	565
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,469	5,505
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	89	143
Impaired Financing Receivable, Recorded Investment	10,165	12,418
Impaired Financing Receivable, Unpaid Principal Balance	10,537	12,790
Impaired Financing Receivable, Average Recorded Investment	11,502	12,951
Impaired Financing Receivable, Interest Income, Cash Basis Method	449	354
Home Equity Line of Credit [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,779	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,779	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	413	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	36	37
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	36	37
Impaired Financing Receivable, Related Allowance	20	22
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	36	3
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	1	0
Impaired Financing Receivable, Recorded Investment	1,815	37
Impaired Financing Receivable, Unpaid Principal Balance	1,815	37
Impaired Financing Receivable, Average Recorded Investment	449	3
Impaired Financing Receivable, Interest Income, Cash Basis Method	1	0
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	125	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	250	0
Impaired Financing Receivable, Related Allowance	125	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	10	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, Recorded Investment	125	0
Impaired Financing Receivable, Unpaid Principal Balance	250	0
Impaired Financing Receivable, Average Recorded Investment	10	0
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 0	$ 0

Loans Receivable and Credit Q75

Loans Receivable and Credit Quality Troubled Debt Restructured Loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Loans	Dec. 31, 2016USD ($)Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	1	9
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 108	$ 10,369
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 109	$ 10,206
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 1,276
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0	3
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 7,384
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 7,209
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0
Commercial Loan [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		2
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 7,209
Commercial Loan [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Loan [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Loan [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		1
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Tax Exempt [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0
Commercial Tax Exempt [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Tax Exempt [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Tax Exempt [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Tax Exempt [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0	1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 1,276
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 1,276
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 1,276
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Real Estate Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Commercial Real Estate Portfolio Segment [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		1
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 1,276
Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0
Construction Loans [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Construction Loans [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Construction Loans [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Construction Loans [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	1	5
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 108	$ 1,709
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 109	$ 1,721
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0
Residential Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Residential Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		4
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 519
Residential Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		1
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 1,202
Residential Portfolio Segment [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0
Home Equity Line of Credit [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Home Equity Line of Credit [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Home Equity Line of Credit [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Home Equity Line of Credit [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Consumer Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Consumer Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0
Consumer Portfolio Segment [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans		0
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 0

Loans Receivable and Credit Q76

Loans Receivable and Credit Quality Loans Text Disclosures (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Deferred Income	$ 6,900	$ 5,900
Servicing Asset	41,400	58,600
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0	0
Financing Receivable, Modifications, Recorded Investment	13,600	18,100
Loans and Leases Receivable, Impaired, Commitment to Lend	0	0
Performing Financial Instruments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 11,100	$ 12,400

Allowance for Loan Losses Allow

Allowance for Loan Losses Allowance Rollforward (Details) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								$ 78,077								$ 78,500		$ 78,077	$ 78,500	$ 75,838
Provision/ (credit) for loan losses		$ (942)	[1]	$ (432)		$ (6,114)		(181)	[1]	$ (1,128)	[1]	$ (138)		$ (2,535)		(3,133)	[1]	(7,669)	(6,935)	(1,555)
Loans charged-off																		(863)	(3,949)	(2,036)
Financing Receivable, Allowance for Credit Losses, Recovery																		5,197	10,461	6,253
Loans and Leases Receivable, Allowance, End of Period		74,742								78,077								74,742	78,077	78,500
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period																15,814			15,814	14,114
Provision/ (credit) for loan losses																				(518)
Loans charged-off																				(253)
Financing Receivable, Allowance for Credit Losses, Recovery																				2,471
Loans and Leases Receivable, Allowance, End of Period																				15,814
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period																44,215			44,215	43,854
Provision/ (credit) for loan losses																				(721)
Loans charged-off																				(1,400)
Financing Receivable, Allowance for Credit Losses, Recovery																				2,482
Loans and Leases Receivable, Allowance, End of Period																				44,215
Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period																6,322			6,322	4,041
Provision/ (credit) for loan losses																				1,123
Loans charged-off																				0
Financing Receivable, Allowance for Credit Losses, Recovery																				1,158
Loans and Leases Receivable, Allowance, End of Period																				6,322
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period																10,544			10,544	10,374
Provision/ (credit) for loan losses																				342
Loans charged-off																				(313)
Financing Receivable, Allowance for Credit Losses, Recovery																				141
Loans and Leases Receivable, Allowance, End of Period																				10,544
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period																1,085			1,085	1,003
Provision/ (credit) for loan losses																				82
Loans charged-off																				0
Financing Receivable, Allowance for Credit Losses, Recovery																				0
Loans and Leases Receivable, Allowance, End of Period																				1,085
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period																520			520	382
Provision/ (credit) for loan losses																				207
Loans charged-off																				(70)
Financing Receivable, Allowance for Credit Losses, Recovery																				1
Loans and Leases Receivable, Allowance, End of Period																				520
Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period	[2]							0								0		0	0	2,070
Provision/ (credit) for loan losses	[2]																	0	0	(2,070)
Loans and Leases Receivable, Allowance, End of Period	[2]									0									0	0
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								391								520		391	520
Provision/ (credit) for loan losses																		619	(63)
Loans charged-off																		(412)	(93)
Financing Receivable, Allowance for Credit Losses, Recovery																		32	27
Loans and Leases Receivable, Allowance, End of Period		630								391								630	391	520
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								1,035								1,085		1,035	1,085
Provision/ (credit) for loan losses																		(200)	(50)
Loans charged-off																		0	0
Financing Receivable, Allowance for Credit Losses, Recovery																		0	0
Loans and Leases Receivable, Allowance, End of Period		835								1,035								835	1,035	1,085
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								10,449								10,544		10,449	10,544
Provision/ (credit) for loan losses																		(665)	445
Loans charged-off																		(58)	(605)
Financing Receivable, Allowance for Credit Losses, Recovery																		47	65
Loans and Leases Receivable, Allowance, End of Period		9,773								10,449								9,773	10,449	10,544
Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								3,039								6,322		3,039	6,322
Provision/ (credit) for loan losses																		1,885	(4,000)
Loans charged-off																		0	(400)
Financing Receivable, Allowance for Credit Losses, Recovery																		25	1,117
Loans and Leases Receivable, Allowance, End of Period		4,949								3,039								4,949	3,039	6,322
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								50,412								44,215		50,412	44,215
Provision/ (credit) for loan losses																		(8,213)	157
Loans charged-off																		0	0
Financing Receivable, Allowance for Credit Losses, Recovery																		4,621	6,040
Loans and Leases Receivable, Allowance, End of Period		46,820								50,412								46,820	50,412	44,215
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning of Period								$ 12,751								$ 15,814		12,751	15,814
Provision/ (credit) for loan losses																		(1,095)	(3,424)
Loans charged-off																		(393)	(2,851)
Financing Receivable, Allowance for Credit Losses, Recovery																		472	3,212
Loans and Leases Receivable, Allowance, End of Period		$ 11,735								$ 12,751								$ 11,735	$ 12,751	$ 15,814
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	As of December 31, 2015, the unallocated reserve was allocated to the qualitative factors as part of the general reserve (ASC 450). The allocation had no effect on the 2015 provision/ (credit) for loan losses.

Allowance for Loan Losses All78

Allowance for Loan Losses Allowance by Impairment Analysis Method (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 22,577	$ 26,030
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	654	1,135
Financing Receivable, Collectively Evaluated for Impairment	6,482,451	6,088,324
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	74,088	76,942
Total loans	6,505,028	6,114,354
Loans and Leases Receivable, Allowance	74,742	78,077	$ 78,500	$ 75,838
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	939,690	1,009,974
Loans and Leases Receivable, Allowance			15,814	14,114
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,440,220	2,302,244
Loans and Leases Receivable, Allowance			44,215	43,854
Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	164,990	104,839
Loans and Leases Receivable, Allowance			6,322	4,041
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,682,533	2,379,861
Loans and Leases Receivable, Allowance			10,544	10,374
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	99,958	118,817
Loans and Leases Receivable, Allowance			1,085	1,003
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	177,637	198,619
Loans and Leases Receivable, Allowance			520	$ 382
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	125	0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	125	0
Financing Receivable, Collectively Evaluated for Impairment	177,512	198,619
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	505	391
Total loans	177,637	198,619
Loans and Leases Receivable, Allowance	630	391	520
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	1,815	37
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	20	22
Financing Receivable, Collectively Evaluated for Impairment	98,143	118,780
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	815	1,013
Total loans	99,958	118,817
Loans and Leases Receivable, Allowance	835	1,035	1,085
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	10,165	12,418
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	89	565
Financing Receivable, Collectively Evaluated for Impairment	2,672,368	2,367,443
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	9,684	9,884
Total loans	2,682,533	2,379,861
Loans and Leases Receivable, Allowance	9,773	10,449	10,544
Construction Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	109	179
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	0
Financing Receivable, Collectively Evaluated for Impairment	164,881	104,660
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	4,949	3,039
Total loans	164,990	104,839
Loans and Leases Receivable, Allowance	4,949	3,039	6,322
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	8,687	11,603
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	362	548
Financing Receivable, Collectively Evaluated for Impairment	2,431,533	2,290,641
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	46,458	49,864
Total loans	2,440,220	2,302,244
Loans and Leases Receivable, Allowance	46,820	50,412	44,215
Commercial and Industrial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	1,676	1,793
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	58	0
Financing Receivable, Collectively Evaluated for Impairment	938,014	1,008,181
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	11,677	12,751
Total loans	939,690	1,009,974
Loans and Leases Receivable, Allowance	$ 11,735	$ 12,751	$ 15,814

Allowance for Loan Losses All79

Allowance for Loan Losses Allowance Text (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Allowance	$ 74,742,000	$ 78,077,000	$ 78,500,000	$ 75,838,000
Loans and Leases Receivable, Net of Deferred Income	6,505,028,000	6,114,354,000
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 0	$ 0

Premises and Equipment Componen

Premises and Equipment Components of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 93,938	$ 102,346
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	56,298	70,519
Premises and equipment, net	37,640	31,827
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	51,161	46,031
Furniture Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	39,618	53,156
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 3,159	$ 3,159

Premises and Equipment Future M

Premises and Equipment Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 21,066
Operating Leases, Future Minimum Payments, Due in Two Years	20,504
Operating Leases, Future Minimum Payments, Due in Three Years	19,718
Operating Leases, Future Minimum Payments, Due in Four Years	19,460
Operating Leases, Future Minimum Payments, Due in Five Years	19,221
Operating Leases, Future Minimum Payments, Due Thereafter	58,076
Operating Leases, Future Minimum Payments Due	$ 158,045

Premises and Equipment Text Det

Premises and Equipment Text Details - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation	$ 8,106	$ 6,838	$ 6,590
Operating Leases, Rent Expense, Net	$ 21,400	$ 19,600	$ 19,000

Goodwill and Other Intangible83

Goodwill and Other Intangible Assets Carrying Value of Goodwill Rollforward (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Goodwill [Line Items]
Goodwill, Period Increase (Decrease)						$ 0
Goodwill, Beginning of Year		$ 142,554,000		$ 152,082,000
Goodwill, Acquired During Period		0		0
Goodwill, Impairment Loss		(24,901,000)		(9,528,000)		0
Goodwill, Transfers		(42,055,000)
Goodwill, End of Year		75,598,000		142,554,000		152,082,000
Private Banking Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning of Year		0		0
Goodwill, Impairment Loss		0		0
Goodwill, Transfers		0
Goodwill, End of Year		0		0		0
Wealth Management and Trust Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning of Year		34,777,000		44,305,000
Goodwill, Impairment Loss		0		(9,528,000)
Goodwill, Transfers		0
Goodwill, End of Year		34,777,000		34,777,000		44,305,000
Investment Managers Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning of Year		66,955,000	[1]	66,955,000
Goodwill, Impairment Loss		(24,901,000)	[1]	0
Goodwill, Written off Related to Sale of Business Unit	[1]	42,054,000
Goodwill, End of Year		0	[1],[2]	66,955,000	[1]	66,955,000
Wealth Advisors Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning of Year		40,822,000	[3]	40,822,000
Goodwill, Impairment Loss		0	[3]	0
Goodwill, Transfers	[3]	(1,000)
Goodwill, End of Year		$ 40,821,000	[3],[4]	$ 40,822,000	[3]	$ 40,822,000
[1]	Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017.
[2]	Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017.
[3]	Adjusted for rounding.
[4]	Adjusted for rounding.

Goodwill and Other Intangible84

Goodwill and Other Intangible Assets Goodwill and Accumulated Impairment Charges (Details) - USD ($) $ in Thousands	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Goodwill [Line Items]
Goodwill, Gross	$ 194,569		$ 236,624
Goodwill, Impaired, Accumulated Impairment Loss	(118,971)		(94,070)
Goodwill	75,598		142,554		$ 152,082
Private Banking Segment [Member]
Goodwill [Line Items]
Goodwill, Gross	34,281		34,281
Goodwill, Impaired, Accumulated Impairment Loss	(34,281)		(34,281)
Goodwill	0		0		0
Wealth Management and Trust Segment [Member]
Goodwill [Line Items]
Goodwill, Gross	44,305		44,305
Goodwill, Impaired, Accumulated Impairment Loss	(9,528)		(9,528)
Goodwill	34,777		34,777		44,305
Investment Managers Segment [Member]
Goodwill [Line Items]
Goodwill, Gross	75,162	[1]	117,216
Goodwill, Impaired, Accumulated Impairment Loss	(75,162)	[1]	(50,261)
Goodwill	0	[1],[2]	66,955	[2]	66,955
Wealth Advisors Segment [Member]
Goodwill [Line Items]
Goodwill, Gross	40,821	[3]	40,822
Goodwill, Impaired, Accumulated Impairment Loss	0	[3]	0
Goodwill	$ 40,821	[3],[4]	$ 40,822	[4]	$ 40,822
[1]	Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017.
[2]	Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017.
[3]	Adjusted for rounding.
[4]	Adjusted for rounding.

Goodwill and Other Intangible85

Goodwill and Other Intangible Assets Goodwill Text (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill, Acquired During Period	$ 0		$ 0
Goodwill, Impairment Loss	$ 24,901		$ 9,528	$ 0
Goodwill, Impaired, Facts and Circumstances Leading to Impairment	The decline in fair value and the related goodwill impairment was related to the fair market value impacts of the Anchor sale transaction. Due to the limited interest and terms of the transaction that were required for a mutual agreement, the fair value obtained was substantially below the carrying value. The fair value was based on the terms of the sale transaction.
Long Lived Assets Held-for-sale, Description			The rationale for the sale was to better position the Company’s resources within the Southern California market.
Anchor [Member]
Goodwill [Line Items]
Proceeds from Sales of Business, Affiliate and Productive Assets	$ 32,000
Proceeds from Divestiture of Interest in Subsidiaries and Affiliates	15,000
Goodwill, Impairment Loss	$ 24,900
Long Lived Assets Held-for-sale, Description	The rationale for the sale is to focus the Company’s resources in businesses where we can offer holistic financial advice, along with integrated wealth management, trust, and private banking capabilities. This transaction will also generate additional capital for us to reinvest in a more focused Company.
Anchor [Member]
Goodwill [Line Items]
Goodwill, Impaired, Method for Fair Value Determination	In December 2017, the Company entered into an agreement to sell its entire ownership interest in Anchor in a transaction that will result in Anchor being majority owned by members of its management team. The Company will receive approximately $32 million of cash at closing and future revenue share payments that, at signing, have a net present value of approximately $15 million, subject to purchase price adjustments. The Company’s annual goodwill impairment test for Anchor resulted in a fourth quarter of 2017 goodwill impairment charge of $24.9 million.
Investment Managers Segment [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	$ 24,901	[1]	$ 0
Wealth Management and Trust Segment [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss	$ 0		$ 9,528
Goodwill, Impaired, Method for Fair Value Determination			Boston Private Wealth failed its Step 1 test and the Company performed a Step 2 test to determine the amount of goodwill impairment, if any. The estimated fair value of Boston Private Wealth was $68.0 million as compared to a carrying value of $76.9 million, resulting in a deficit of $8.9 million, or 11.6%. Because the estimated fair value of Boston Private Wealth was lower than its carrying value, the Company was required to perform a Step 2 valuation. The results of the Step 2 valuation indicated an implied fair value of goodwill of $34.8 million as compared to the book value of $44.3 million, or a deficiency of $9.5 million. The resulting deficiency was recorded as a goodwill impairment charge within operating expenses in the fourth quarter of 2016. As a result of the goodwill impairment, the carrying value of goodwill at Boston Private Wealth was reduced to $34.8 million.
[1]	Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017.

Goodwill and Other Intangible86

Goodwill and Other Intangible Assets Gross and Net Carrying Amounts of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 37,453	$ 73,553
Finite-Lived Intangible Assets, Accumulated Amortization		21,370	46,828
Finite-Lived Intangible Assets, Net		16,083	26,725
Advisory Contracts [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	[1]	37,313	71,513
Finite-Lived Intangible Assets, Accumulated Amortization	[1]	21,370	46,828
Finite-Lived Intangible Assets, Net	[1]	15,943	24,685
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	[1]	140	2,040
Finite-Lived Intangible Assets, Accumulated Amortization	[1]	0	0
Finite-Lived Intangible Assets, Net	[1]	$ 140	$ 2,040
[1]	Intangible assets of Anchor are classified as held for sale as of December 31, 2017.

Goodwill and Other Intangible87

Goodwill and Other Intangible Assets Intangible Assets Text (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 0	$ 0
Amortization of Intangible Assets	$ 5,601	$ 6,282	$ 6,711
Finite-Lived Intangible Assets, Remaining Amortization Period	6 years 8 months 6 days

Goodwill and Other Intangible88

Goodwill and Other Intangible Assets Future Amortization Expense on Intangible Assets (Details) $ in Thousands	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 2,970
Finite-Lived Intangible Assets, Amortization Expense, Year Two	2,848
Finite-Lived Intangible Assets, Amortization Expense, Year Three	2,588
Finite-Lived Intangible Assets, Amortization Expense, Year Four	2,110
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 2,056

Derivatives and Hedging Activ89

Derivatives and Hedging Activities Derivatives Fair Value and Balance Sheet Classification (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	$ 19,133	$ 17,047
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]	(19,143)	(17,606)
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	555	0
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]	(80)	(1,040)
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	18,575	17,032
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]	(18,953)	(16,560)
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	2	0
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]	(2)	0
Loan Participations and Assignments [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1	15
Loan Participations and Assignments [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]	$ (108)	$ (6)
[1]	For additional details, see Part II. Item 8. “Financial Statements and Supplementary Data - Note 21: Fair Value of Financial Instruments.”

Derivatives and Hedging Activ90

Derivatives and Hedging Activities Effect of Derivative Instruments on Statement of Operations (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net		$ (11)	$ 6
Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	336	(799)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		(1,168)	(1,672)
Interest Rate Contract [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1]	336	(799)
Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ (1,168)	$ (1,672)
[1]	There was an additional $(11) thousand loss related to the ineffective portion for the year ended December 31, 2017 and an additional $6 thousand gain related to the ineffective portion for the year ended December 31, 2016.

Derivatives and Hedging Activ91

Derivatives and Hedging Activities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative, Collateral, Obligation to Return Cash	$ 3.1	$ 3.4
Derivative, Collateral, Right to Reclaim Securities	$ 2.3	$ 1.9

Derivatives and Hedging Activ92

Derivatives and Hedging Activities Cash Flow Hedges Text Description (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)contracts	Dec. 31, 2016USD ($)
Derivative [Line Items]
Loss on Cash Flow Hedge Ineffectiveness	$ 0	$ 0
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 0.2
Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 1,100	1,100
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount	0.2	$ 0.1
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 100
Number of Interest Rate Derivatives Held | contracts	6
Bank $60m LIBOR Swap 2017 effective 3/22/17 [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 60
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Derivative, Term of Contract	2 years 3 months
Derivative, Inception Date	Mar. 22, 2017
Derivative, Fixed Interest Rate	1.65%
Bank $60m LIBOR Swap 2017 effective 3/22/17 [Member] | Weighted Average [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.61%
Bank $40m LIBOR Swap 2017 effective 3/22/17 [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 40
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Derivative, Term of Contract	1 year 9 months
Derivative, Inception Date	Mar. 22, 2017
Derivative, Fixed Interest Rate	1.55%
Bank $40m LIBOR Swap 2017 effective 3/22/17 [Member] | Weighted Average [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.61%
Bank $25m LIBOR Swap effective 8/1/13 [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 25
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Derivative, Inception Date	Aug. 1, 2013
Bank $25m LIBOR Swap effective 8/1/13 [Member] | Minimum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	4 years
Derivative, Fixed Interest Rate	1.68%
Bank $25m LIBOR Swap effective 8/1/13 [Member] | Weighted Average [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.95%
Bank $25m LIBOR Swap effective 8/1/13 [Member] | Maximum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	6 years
Derivative, Fixed Interest Rate	2.32%
Bank $25m LIBOR Swap effective 3/1/14 [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 25
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Derivative, Inception Date	Mar. 1, 2014
Bank $25m LIBOR Swap effective 3/1/14 [Member] | Minimum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	4 years
Derivative, Fixed Interest Rate	1.68%
Bank $25m LIBOR Swap effective 3/1/14 [Member] | Weighted Average [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.95%
Bank $25m LIBOR Swap effective 3/1/14 [Member] | Maximum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	6 years
Derivative, Fixed Interest Rate	2.32%
Bank $25m LIBOR Swap 2013 effective 6/1/14 [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 25
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Derivative, Inception Date	Jun. 1, 2014
Bank $25m LIBOR Swap 2013 effective 6/1/14 [Member] | Minimum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	4 years
Derivative, Fixed Interest Rate	1.68%
Bank $25m LIBOR Swap 2013 effective 6/1/14 [Member] | Weighted Average [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.95%
Bank $25m LIBOR Swap 2013 effective 6/1/14 [Member] | Maximum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	6 years
Derivative, Fixed Interest Rate	2.32%
Bank $25m LIBOR Swap effective 9/2/14 [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 25
Objectives for Using Derivative Instruments	The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements.
Derivative, Inception Date	Sep. 2, 2014
Bank $25m LIBOR Swap effective 9/2/14 [Member] | Minimum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	4 years
Derivative, Fixed Interest Rate	1.68%
Bank $25m LIBOR Swap effective 9/2/14 [Member] | Weighted Average [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	1.95%
Bank $25m LIBOR Swap effective 9/2/14 [Member] | Maximum [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Private Banking Segment [Member]
Derivative [Line Items]
Derivative, Term of Contract	6 years
Derivative, Fixed Interest Rate	2.32%

Derivatives and Hedging Activ93

Derivatives and Hedging Activities Non-designated Hedges Text description (Details) - Not Designated as Hedging Instrument [Member] $ in Millions	Dec. 31, 2017USD ($)contracts	Dec. 31, 2016USD ($)contracts
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held | contracts	142	136
Derivative, Notional Amount	$ 1,100	$ 1,100
Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held | contracts	3	1
Derivative, Notional Amount	$ 0.2	$ 0.1
Loan Participations and Assignments [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held | contracts	6	2
Other Liabilities [Member] | Loan Participations and Assignments [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 48	$ 13.3
Other Assets [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 6.1	$ 6.1

Derivatives and Hedging Activ94

Derivatives and Hedging Activities Derivatives not designated as hedges, effect on statement of operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Description of Location of Gain (Loss) on Interest Rate Derivative on Income Statement	Other income/(expense)
Description of Location of Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments in Financial Statements	Other income/(expense)
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (497)	$ 600
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(851)	596
Not Designated as Hedging Instrument [Member] | Loan Participations and Assignments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 354	$ 4

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Deposits by Type [Line Items]
Noninterest-bearing Domestic Deposit, Demand		$ 2,025,690	$ 1,753,648
Deposits, Savings and NOW	[1]	716,296	652,819
Deposits, Money Market Deposits	[1]	3,121,811	3,102,048
Time Deposits, Less than $100,000	[1]	250,070	236,001
Time deposits $100,000 to less than $250,000	[1]	82,665	100,570
Time Deposits, at or Above FDIC Insurance Limit		313,714	240,060
Deposits		$ 6,510,246	$ 6,085,146
[1]	Includes brokered deposits.

Deposits Schedule of Maturities

Deposits Schedule of Maturities of Certificates of Deposit (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Time Deposits [Line Items]
Time Deposit Maturities, Less than Three Months	$ 214,594	$ 140,304
Time Deposit Maturities, Three to Six Months	183,780	73,522
Time Deposit Maturities, Six to Twelve Months	133,873	213,802
Time Deposit Maturities, Next Twelve Months	532,247	427,628
Time Deposit Maturities, Year Two	79,926	115,099
Time Deposit Maturities, Year Three	32,165	14,492
Time Deposit Maturities, Year Four	2,083	17,437
Time Deposit Maturities, Year Five	25	1,972
Time Deposit Maturities, after Year Five	3	3
Time Deposits	$ 646,449	$ 576,631

Deposits Deposits Text Details

Deposits Deposits Text Details (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deposits Text Disclosures [Abstract]
Interest Expense, Time Deposits, $100,000 or More	$ 3.1	$ 2	$ 2.3
Deposit Liabilities Reclassified as Loans Receivable	$ 0.4	$ 0.2

Federal Funds Purchased and S98

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Federal Funds Purchased	$ 30,000	$ 80,000	$ 0
Securities Sold under Agreements to Repurchase	32,169	59,624	58,215
Available-for-sale Securities Pledged as Collateral	144,300	182,700
Federal Funds Lines of Credit, Amount of Available Unused Funds	435,000	485,000
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Short-term Debt, Maximum Month-end Outstanding Amount	100,000	180,000	102,000
Short-term Debt, Average Outstanding Amount	$ 22,742	$ 29,542	$ 10,008
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.50%	0.75%	0.00%
Debt Instrument, Interest Rate During Period	1.19%	0.54%	0.31%
Securities Sold under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Short-term Debt, Maximum Month-end Outstanding Amount	$ 67,249	$ 77,466	$ 75,313
Short-term Debt, Average Outstanding Amount	$ 58,872	$ 66,282	$ 64,320
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.09%	0.05%	0.05%
Debt Instrument, Interest Rate During Period	0.09%	0.05%	0.05%

Federal Home Loan Bank Borrow99

Federal Home Loan Bank Borrowings (Details) $ in Thousands	Dec. 31, 2017USD ($)
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months	$ 529,720
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due within One Year of Balance Sheet Date	1.55%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Two	$ 59,018
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, One to Two Years from Balance Sheet Date	1.45%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three	$ 54,365
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date	2.89%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Four	$ 37,045
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Three to Four Years from Balance Sheet Date	2.01%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Five	$ 3,985
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Four to Five Years from Balance Sheet Date	1.93%
Federal Home Loan Bank, Advances, Maturities Summary, Due after Year Five	$ 9,548
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, after Five Years from Balance Sheet Date	2.57%
Federal Home Loan Bank, Advances	$ 693,681
Weighted Average [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Weighted Average Interest Rate	1.69%

Federal Home Loan Bank Borro100

Federal Home Loan Bank Borrowings FHLB Text (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Description of Collateral Pledged	Borrowings from the FHLB are secured by the Bank’s stock investment in the FHLB and a blanket lien on “qualified collateral” defined principally as a percentage of the principal balance of certain types of mortgage loans. The stock investment cannot be used for additional borrowing collateral. The percentage of collateral valuation from the FHLB varies between 50% and 82% based on the underlying collateral.
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	$ 2,500,000	$ 2,300,000
Federal Home Loan Bank borrowings	693,681	734,205
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	1,200,000	900,000
FHLB Borrowings Callable Before Maturity	0	$ 5,000
Stock in Federal Home Loan Banks	$ 46,100
Minimum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank Stock Ownership as a Percent of Outstanding Advances	3.00%
Maximum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank Stock Ownership as a Percent of Outstanding Advances	4.00%

Junior Subordinated Debentur101

Junior Subordinated Debentures (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	$ 106,363	$ 106,363
Junior subordinated debentures, Maturities, Repayments of Principal after Year Five	106,363	106,363
Boston Private Capital Trust II [Member]
Debt Instrument [Line Items]
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	103,093	103,093
Junior subordinated debentures, Maturities, Repayments of Principal after Year Five	103,093	103,093
Boston Private Capital Trust I [Member]
Debt Instrument [Line Items]
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	3,270	3,270
Junior subordinated debentures, Maturities, Repayments of Principal after Year Five	$ 3,270	$ 3,270

Junior Subordinated Debentur102

Junior Subordinated Debentures Boston Private Capital Trust II Terms (Details) - Boston Private Capital Trust II [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 100
Debt Instrument, Frequency of Periodic Payment	quarterly
Debt Instrument, Description of Variable Rate Basis	three-month LIBOR plus
Debt Instrument, Basis Spread on Variable Rate	1.68%
Debt Instrument, Interest Rate Terms	provided, however, that the interest rate does not exceed the highest rate permitted by New York law, and may be modified by the U.S. law of general application
Debt Instrument, Interest Rate at Period End	3.02%
Assets Held-in-trust	$ 3.1	$ 3.1
Debt Instrument, Maturity Date	Dec. 30, 2035
Debt Instrument, Call Feature	became redeemable after December 30, 2010
Debt Instrument, Covenant Compliance	At December 31, 2017, the Company was in compliance with the above covenants.	At December 31, 2016, the Company was in compliance with the above covenants.

Junior Subordinated Debentur103

Junior Subordinated Debentures Boston Private Capital Trust I Terms (Details) - Boston Private Capital Trust I [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 105
Junior Subordinated Debt, Liquidation Price per Share	$ 50
Debt Instrument, Frequency of Periodic Payment	quarterly
Debt Instrument, Interest Rate Terms	fixed
Debt Instrument, Interest Rate at Period End	4.875%
Debt Instrument, Maturity Date	Oct. 1, 2034
Assets Held-in-trust	$ 3.2	$ 3.2

Noncontrolling Interests Compon

Noncontrolling Interests Components of Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	$ 17,461	$ 16,972
Stockholders' Equity Attributable to Noncontrolling Interest	22,647	21,133
Nonredeemable Noncontrolling Interest	5,186	4,161
Anchor [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable and Nonredeemable Noncontrolling Interest	9,761	10,934
Nonredeemable Noncontrolling Interest	2,900	2,000
BOS [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable and Nonredeemable Noncontrolling Interest	8,057	6,782
Nonredeemable Noncontrolling Interest	2,300	2,200
DGHM [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	$ 4,829	$ 3,417

Noncontrolling Interests Redeem

Noncontrolling Interests Redeemable Noncontrolling Interests Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interests, Equity, Carrying Amount, Beginning of Period							$ 16,972										$ 16,972
Nonredeemable Noncontrolling Interest, Beginning of Period							4,161										4,161
Net Income (Loss) Attributable to Noncontrolling Interest	$ 1,278	[1]	$ 1,074		$ 1,150		966	[1]	$ 1,147	[1]	$ 1,110		$ 989		$ 911	[1]	4,468	$ 4,157	$ 4,407
Redeemable Noncontrolling Interests, Equity, Carrying Amount, End of Period	17,461								16,972								17,461	16,972
Nonredeemable Noncontrolling Interest, End of Period	5,186								4,161								5,186	4,161
Anchor [Member]
Redeemable Noncontrolling Interest [Line Items]
Nonredeemable Noncontrolling Interest, Beginning of Period							2,000										2,000
Nonredeemable Noncontrolling Interest, End of Period	2,900								2,000								2,900	2,000
Redeemable Noncontrolling Interest [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interests, Equity, Carrying Amount, Beginning of Period							16,972								18,088		16,972	18,088	20,905
Net Income (Loss) Attributable to Noncontrolling Interest																	3,354	3,204	3,575
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders																	(3,277)	(3,112)	(4,189)
Redeemable Noncontrolling Interest Increase, Purchase or Sale of Additional Ownership Interest																			(1,666)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests																	235	(765)
Noncontrolling Interest, Increase from Subsidiary Equity Issuance																	0	0	(1,652)
Amortization of Noncontrolling Interest Equity Compensation																	413	449	0
Noncontrolling Interest, Period Increase (Decrease)																	(236)	(892)	1,115
Redeemable Noncontrolling Interests, Equity, Carrying Amount, End of Period	17,461								16,972								17,461	16,972	18,088
Noncontrolling Interest [Member]
Redeemable Noncontrolling Interest [Line Items]
Nonredeemable Noncontrolling Interest, Beginning of Period							$ 4,161								$ 3,393		4,161	3,393	386
Net Income (Loss) Attributable to Noncontrolling Interest																	1,114	953	832
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders																	(1,083)	(942)	(422)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests																	85	(134)	419
Noncontrolling Interest, Increase from Subsidiary Equity Issuance																	0	0	1,652
Amortization of Noncontrolling Interest Equity Compensation																	935	747	472
Noncontrolling Interest, Period Increase (Decrease)																	(26)	144	54
Nonredeemable Noncontrolling Interest, End of Period	$ 5,186								$ 4,161								$ 5,186	$ 4,161	$ 3,393
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.

Noncontrolling Interests Text D

Noncontrolling Interests Text Details (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016		Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Noncontrolling Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interest	$ 1,278	[1]	$ 1,074		$ 1,150		$ 966		$ 1,147	[1]	$ 1,110		$ 989		$ 911		$ 4,468	$ 4,157	$ 4,407
Redeemable noncontrolling interests	17,461								16,972								17,461	16,972
Nonredeemable Noncontrolling Interest	5,186								4,161								5,186	4,161
Anchor [Member]
Noncontrolling Interest [Line Items]
Nonredeemable Noncontrolling Interest	2,900								2,000								2,900	2,000
Redeemable and Nonredeemable Noncontrolling Interest	9,761								10,934								9,761	10,934
BOS [Member]
Noncontrolling Interest [Line Items]
Nonredeemable Noncontrolling Interest	2,300								2,200								2,300	2,200
Redeemable and Nonredeemable Noncontrolling Interest	8,057								6,782								8,057	6,782
DGHM [Member]
Noncontrolling Interest [Line Items]
Redeemable noncontrolling interests	$ 4,829								$ 3,417								$ 4,829	$ 3,417
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.

Equity Preferred Stock (Details

Equity Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Depositary Shares, Issued	2,000,000	2,000,000
Preferred Stock, Par Value Per Share	$ 1	$ 1
Preferred Stock, Value, Issued	$ 47,753	$ 47,753
Preferred Stock, Redemption Terms	The Company may redeem the Series D preferred stock on any dividend payment date on or after June 15, 2018; or within 90 days of a change, proposed change, administrative decision, or re-interpretation in the laws, regulations, or guidelines regarding the regulatory capital treatment of the Series D preferred stock.
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Contract Terms	Each Depositary Share represents a 1/40th interest in a share
Preferred Stock, Dividend Rate, Percentage	6.95%
Preferred Stock, Par Value Per Share	$ 1
Preferred Stock, Liquidation Preference Per Share	$ 1,000	$ 1,000
Preferred Stock, Value, Issued	$ 47,753	$ 47,800

Equity Common Stock (Details)

Equity Common Stock (Details) - shares	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Common Stock, Shares Authorized	170,000,000	170,000,000
Common Stock, Shares, Issued	84,208,538	83,731,769
Common Stock, Capital Shares Reserved for Future Issuance	85,791,462	86,268,231

Equity Warrants to Purchase Com

Equity Warrants to Purchase Common Stock (Details)	12 Months Ended
	Dec. 31, 2017$ / sharesshares	[1]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding	1,692,755
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right	1.14	[2]
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 7.011	[2]
Class of Warrant or Right, Date from which Warrants or Rights Exercisable	Nov. 21, 2008
Class of Warrant or Right, Date until which Warrants or Rights Exercisable	Nov. 21, 2018
[1]	The TARP warrants, while initially issued to the Treasury, were purchased from the Treasury by unrelated third parties at a market rate.
[2]	Per the terms of the TARP warrant agreement, the exercise price and number of shares issuable upon exercise may be adjusted ratably for dividends paid on the Company’s common stock that exceed the dividend rate at the time the warrants were issued, at which time the Company paid quarterly dividends of $0.01 per share. The current warrant share number and current exercise price of the warrant reflect the warrant as adjusted for common stock dividends through February 2, 2018, the latest dividend record date prior to the filing of this Annual Report.

Equity Other Comprehensive Inco

Equity Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2017	[2]	Sep. 30, 2017	[2]	Jun. 30, 2017	[2]	Mar. 31, 2017	[2]	Dec. 31, 2016	[2]	Sep. 30, 2016	[2]	Jun. 30, 2016	[2]	Mar. 31, 2016	[2]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, [Abstract]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax																		$ 7,782		$ (18,913)		$ (2,494)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax																		3,063		(7,555)		(1,145)
Unrealized gain/ (loss) on securities available-for-sale																		4,719		(11,358)		(1,349)
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, before Tax																		376		521		236
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax																		154		190		97
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax																		(222)		(331)		(139)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax																		7,406		(19,434)		(2,730)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax																		2,909		(7,745)		(1,242)
Net unrealized gain/ (loss) on securities available-for-sale																		4,497		(11,689)		(1,488)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax																		325		(793)		(2,642)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax																		135		(332)		(1,088)
Unrealized gain/ (loss) on cash flow hedges																		190		(461)		(1,554)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, before Tax																		1,179		1,666		4,052
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax																		491		687		1,698
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax																		688		979		2,354
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax																		1,504		873		1,410
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax																		626		355		610
Net unrealized gain/ (loss) on cash flow hedges																		878		518		800
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract]
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax																		84		200		(193)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax																		34		77		(78)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax																		50		123		(115)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent																		84		200		(193)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax																		34		77		(78)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax																		50		123		(115)
Other Comprehensive Income (Loss), before Tax																		8,994		(18,361)		(1,513)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent																		3,569		(7,313)		(710)
Other comprehensive income/ (loss), net																		5,425		(11,048)		(803)
Net Income Attributable to the Parent Before Tax	[1]																	86,787		102,591		95,317
Income tax expense/(benefit)		$ 21,391		$ 8,289		$ 9,963		$ 6,553		$ 7,247		$ 8,652		$ 7,626		$ 7,438		46,196	[3]	30,963	[3]	30,392	[3]
Net income attributable to the Company		$ (18,280)		$ 19,803		$ 23,406		$ 15,662		$ 17,552		$ 19,636		$ 16,398		$ 18,041		40,591		71,628		64,925
Comprehensive Income (Loss), Before Tax, Attributable to Parent																		95,781		84,230		93,804
Comprehensive Income (Loss), Tax, Attributable to Parent																		49,765		23,650		29,682
Total comprehensive income attributable to the Company, net																		$ 46,016		$ 60,580		$ 64,122
[1]	Pre-tax net income attributable to the Company is calculated as income before income taxes, plus net income from discontinued operations, less net income attributable to noncontrolling interests.
[2]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[3]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.

Equity Change in OCI Recognized

Equity Change in OCI Recognized in Statement of Operations, Line Item (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017	[1]	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of investments, net																	$ 376		$ 521		$ 236
Interest Expense, Junior Subordinated Debentures																	2,919		2,427		3,875
Interest Expense, Deposits																	20,884		16,571		16,002
Income tax expense/(benefit)	$ 21,391		$ 8,289		$ 9,963		$ 6,553		$ 7,247		$ 8,652		$ 7,626		$ 7,438		46,196	[2]	30,963	[2]	30,392	[2]
Net income attributable to the Company	$ (18,280)		$ 19,803		$ 23,406		$ 15,662		$ 17,552		$ 19,636		$ 16,398		$ 18,041		40,591		71,628		64,925
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax																	(688)		(979)		(2,354)
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of investments, net																	376		521		236
Income tax expense/(benefit)																	154		190		97
Net income attributable to the Company																	222		331		139
Hedges related to junior subordinated debt [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense, Junior Subordinated Debentures																	0		0		1,879
Income tax expense/(benefit)																	0		0		804
Net income attributable to the Company																	0		0		(1,075)
Hedges related to deposits [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense, Deposits																	1,179		1,666		2,173
Income tax expense/(benefit)																	491		687		894
Net income attributable to the Company																	$ (688)		$ (979)		$ (1,279)
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.

Equity Accumulated Other Compre

Equity Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income/ (loss), beginning of period	$ (12,548)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	4,719	$ (11,358)	$ (1,349)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	190	(461)	(1,554)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	50	123	(115)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	(222)	(331)	(139)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	688	979	2,354
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	688	979	2,354
Net unrealized gain/ (loss) on securities available-for-sale	4,497	(11,689)	(1,488)
Change in unrealized gain/ (loss) on cash flow hedges, net of tax	878	518	800
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	50	123	(115)
Other comprehensive income/ (loss), net	5,425	(11,048)	(803)
Accumulated other comprehensive income/ (loss), end of period	(8,658)	(12,548)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income/ (loss), beginning of period	(12,548)	(1,500)	(697)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	4,959	(11,696)	(3,018)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	466	648	2,215
Other comprehensive income/ (loss), net	5,425	(11,048)	(803)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	(1,535)
Accumulated other comprehensive income/ (loss), end of period	(8,658)	(12,548)	(1,500)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain/ (loss) on securities available-for-sale, net of tax, beginning of period	(11,194)	495	1,983
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	4,719	(11,358)	(1,349)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	(222)	(331)	(139)
Net unrealized gain/ (loss) on securities available-for-sale	4,497	(11,689)	(1,488)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	(1,443)
Unrealized gain/ (loss) on securities available-for-sale, net of tax, end of period	(8,140)	(11,194)	495
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain/ (loss) on cash flow hedges, net of tax, beginning of period	(605)	(1,123)	(1,923)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	190	(461)	(1,554)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	688	979	2,354
Change in unrealized gain/ (loss) on cash flow hedges, net of tax	878	518	800
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	59
Unrealized gain/ (loss) on cash flow hedges, net of tax, end of period	332	(605)	(1,123)
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gain/ (loss) on other, net of tax, beginning of period	(749)	(872)	(757)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	50	123	(115)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax	0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	50	123	(115)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	(151)
Unrealized gain/ (loss) on other, net of tax, end of period	$ (850)	$ (749)	$ (872)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2017	[1]	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Income from Continuing Operations, Including Portion Attributable to Noncontrolling Interest																		$ 40,189		$ 70,244		$ 62,921
Net Income (Loss) Attributable to Noncontrolling Interest		$ 1,278		$ 1,074		$ 1,150		$ 966		$ 1,147		$ 1,110		$ 989		$ 911		4,468		4,157		4,407
Income (Loss) from Continuing Operations Attributable to Parent																		35,721		66,087		58,514
Noncontrolling Interest, Change in Redemption Value																		(1,412)		(588)		464	[2]
Preferred Stock Dividends and Other Adjustments																		(3,475)		(3,475)		(3,475)
Other Preferred Stock Dividends and Adjustments																		(4,887)		(4,063)		(3,011)
Net Income (Loss) from Continuing Ops Available to Common Stockholders, Basic																		30,834		62,024		55,503	[3]
Net income from discontinued operations		$ 989		$ 1,186		$ 1,063		$ 1,632		$ 1,184		$ 1,047		$ 1,245		$ 2,065		4,870	[4]	5,541	[4]	6,411	[4]
Net income attributable to common shareholders for basic earnings per share calculation																		$ 35,704		$ 67,565		$ 61,914	[3]
Income (Loss) from Continuing Operations, Per Basic Share																		$ 0.37		$ 0.76		$ 0.69
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share																		0.06		0.07		0.08
Earnings (Loss) Per Share, Basic		$ (0.24)	[5]	$ 0.23	[5]	$ 0.28	[5]	$ 0.18	[5]	$ 0.19	[5]	$ 0.23	[5]	$ 0.19	[5]	$ 0.22	[5]	$ 0.43		$ 0.83		$ 0.77
Net Income (Loss) from Continuing Operations Available to Common Stockholders, Diluted																		$ 30,834		$ 62,024		$ 55,503	[3]
Net income attributable to common shareholders for basic earnings per share calculation																		$ 35,704		$ 67,565		$ 61,914
Income (Loss) from Continuing Operations, Per Diluted Share																		$ 0.36		$ 0.74		$ 0.66
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share																		0.06		0.07		0.08
Earnings/ (Loss) Per Share, Diluted		$ (0.24)	[5]	$ 0.22	[5]	$ 0.27	[5]	$ 0.17	[5]	$ 0.19	[5]	$ 0.22	[5]	$ 0.18	[5]	$ 0.21	[5]	0.42		0.81		0.74
Common Stock, Dividends, Per Share, Cash Paid																		$ 0.44		$ 0.40		$ 0.36
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic																				$ 4		$ 90
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic																				8		92
NI To Common SH Difference Between Two Class And Treasury Method																				$ 12		$ 182
Earnings Per Share, Basic, Undistributed																						$ 0.01
WtdAvg Shares OS Recon Between Two Class and Treasury Method																				7,185		167,937
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																		1,000		1,000		1,000
Shares Excluded Due to Exercise Price Exceeding Average Price During Period																		67,000		270,000		548,000
Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding, Basic																		82,430,633		81,264,273		80,885,253
Incremental Common Shares Attributable to Share-based Payment Arrangements																		1,313,953		1,002,153		1,301,448	[3],[6]
Incremental Common Shares Attributable to Call Options and Warrants																		1,057,979		942,700		1,206,389	[6]
Weighted Average Number Diluted Shares Outstanding Adjustment																		2,371,932		1,944,853		2,507,837
Weighted Average Number of Shares Outstanding, Diluted																		84,802,565		83,209,126		83,393,090	[3],[6]
Convertible Debt Securities [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	[7]																	1,000		1,000		1,000
Stock Compensation Plan [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Shares Excluded Due to Exercise Price Exceeding Average Price During Period																		67,000		270,000		548,000	[8]
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	See Part II. Item 8. “Financial Statements and Supplementary Data - Note 14: Noncontrolling Interests” for a description of the redemption values related to the redeemable noncontrolling interests. In accordance with ASC 480, Distinguishing Liabilities from Equity (“ASC 480”), an increase in redemption values from period to period reduces income attributable to common shareholders. Decreases in redemption value from period to period increase income attributable to common shareholders, but only to the extent that the cumulative change in redemption value remains a cumulative increase since adoption of this standard in the first quarter of 2009.
[3]	The Company presents its EPS based on the treasury stock method. The Company reverted to the treasury stock presentation from the two-class presentation due to the immaterial number of participating shares outstanding as of March 31, 2016. There is no difference between the calculation of EPS based on the treasury stock method and the calculation of EPS based on the two-class method for the year ended December 31, 2017.If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2016. Net income attributable to common shareholders would have been reduced by an additional $4 thousand, for the year ended December 31, 2016. The allocation of net income to participating securities would have been $8 thousand for the year ended December 31, 2016, reducing net income attributable to common shareholders by a total of $12 thousand for the same period. Basic EPS would not change. Weighted average diluted shared outstanding would have been reduced by 7,185 shares for the year ended December 31, 2016. Diluted EPS would not change. If the EPS presentation had been based on the two-class method, the following adjustments would have been made to the presentation of EPS for the year ended December 31, 2015. Net income attributable to common shareholders would have been reduced by an additional $90 thousand for the year ended December 31, 2015, and the allocation of net income to participating securities would have been $92 thousand for the same period, reducing net income attributable to common shareholders by a total of $182 thousand, for the same period. Total basic EPS and basic EPS from continuing operations would each decrease by $0.01 per share for the year ended December 31, 2015. Weighted average diluted shares outstanding would have been reduced by 167,937 shares for the same period. Diluted EPS would not change.
[4]	The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively
[5]	Includes the effect of adjustments to net income attributable to the Company to arrive at net income attributable to common shareholders.
[6]	The diluted EPS computations for the years ended December 31, 2017, 2016, and 2015 do not assume the conversion, exercise or contingent issuance of the following shares for the following periods because the result would have been antidilutive for the periods indicated. As a result of the anti-dilution, the potential common shares excluded from the diluted EPS computation are as follows: For the year ended December 31, 2017 2016 2015Shares excluded due to anti-dilution (treasury stock method):(In thousands)Potential common shares from: Convertible trust preferred securities (a)1 1 1Total shares excluded due to anti-dilution1 1 1 For the year ended December 31, 2017 2016 2015Shares excluded due to exercise price exceeding the average market price of common shares during the period (total outstanding):(In thousands)Potential common shares from: Options, restricted stock, or other dilutive securities (b)67 270 548Total shares excluded due to exercise price exceeding the average market price of common shares during the period67 270 548(a) If the effect of the conversion of the trust preferred securities would have been dilutive, an immaterial amount of interest expense, net of tax, related to the convertible trust preferred securities would have been added back to net income attributable to common shareholders for the diluted EPS computation for the years presented.(b)Options to purchase shares of common stock, non-participating performance- and certain time-based restricted stock, and other dilutive securities that were outstanding at period ends were not included in the computation of diluted EPS or in the above anti-dilution table because their exercise or conversion prices were greater than the average market price of the common shares during the respective periods.
[7]	If the effect of the conversion of the trust preferred securities would have been dilutive, an immaterial amount of interest expense, net of tax, related to the convertible trust preferred securities would have been added back to net income attributable to common shareholders for the diluted EPS computation for the years presented.
[8]	Options to purchase shares of common stock, non-participating performance- and certain time-based restricted stock, and other dilutive securities that were outstanding at period ends were not included in the computation of diluted EPS or in the above anti-dilution table because their exercise or conversion prices were greater than the average market price of the common shares during the respective periods.

Income Taxes Components of Inco

Income Taxes Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Income Tax Expense Components [Line Items]
Federal	$ 12,900
Total deferred expense/(benefit)																	$ 22,845		$ 2,777		$ (4,575)
Income tax expense	$ 21,391	[1]	$ 8,289		$ 9,963		$ 6,553		$ 7,247		$ 8,652		$ 7,626		$ 7,438		46,196	[2]	30,963	[2]	30,392	[2]
Income Tax Expense Components, Continuing Operations [Member]
Income Tax Expense Components [Line Items]
Federal																	17,176		20,237		25,631
State																	6,509		7,778		9,183
Total current expense																	23,685		28,015		34,814
Federal																	19,820		1,976		(3,185)
State																	2,691		972		(1,237)
Total deferred expense/(benefit)																	22,511		2,948		(4,422)
Income tax expense																	$ 46,196		$ 30,963		$ 30,392
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.

Income Taxes Income Tax Rate Re

Income Taxes Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense Components [Line Items]
Statutory Federal income tax rate	35.00%	35.00%	35.00%
Re-measurement of deferred tax assets and liabilities	13.70%	0.00%	0.00%
Nondeductible goodwill	10.10%	0.00%	0.00%
Tax-exempt interest, net	(10.30%)	(7.50%)	(7.10%)
State and local income tax, net of Federal tax benefit	6.90%	5.60%	5.50%
Tax credits	(3.10%)	(2.20%)	(1.90%)
Investments in affordable housing projects	2.20%	0.90%	0.90%
Noncontrolling interests	(1.50%)	(1.40%)	(1.60%)
Out-of-period adjustment	0.00%	0.00%	1.30%
Other, net	0.50%	0.20%	0.50%
Effective income tax rate	53.50%	30.60%	32.60%

Income Taxes Components of Defe

Income Taxes Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Allowance for loan and OREO losses	$ 22,782	$ 35,545
Interest on nonaccrual loans	295	548
Stock compensation	3,156	6,079
Deferred and accrued compensation	11,822	19,801
Contingent payments	1,236	1,868
Unrealized loss on investments	3,345	8,264
Other	1,437	905
Gross deferred tax assets	44,073	73,010
Total deferred tax assets	44,073	73,010
Deferred income on repurchase of debt	832	2,692
Goodwill and acquired intangible assets	12,246	12,929
Fixed assets	991	67
Prepaid expenses	347	611
Other	626	1,251
Total gross deferred tax liabilities	15,042	17,550
Net deferred tax asset	$ 29,031	$ 55,460

Income Taxes Unrecognized Tax B

Income Taxes Unrecognized Tax Benefits Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 900	$ 800	$ 800
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	974	1,022	1,067
Additions based on tax positions related to the current year	183	160	163
Additions based on tax positions taken in prior years	227	0	0
Decreases based on the expiration of statute of limitations	(359)	(208)	(208)
Balance at December 31	$ 1,025	$ 974	$ 1,022

Income Taxes Text Details Incom

Income Taxes Text Details Income Tax Components (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense Components [Line Items]
Other Information Pertaining to Income Taxes		On December 22, 2017, H.R. 1, the Tax Act, was enacted by the U.S. government. Substantially all of the provisions of the Tax Act are effective as of January 1, 2018. The Tax Act includes significant changes to the Internal Revenue Code of 1986, as amended, including amendments which significantly change the taxation of business entities. The more significant changes in the Tax Act that impact the Company are the reduction in the federal corporate tax rate from 35% to 21% and the changes to the deductibility of executive compensation, both of which are effective as of January 1, 2018. Under ASC 740, the tax effects of changes in tax laws must be recognized in the period in which the law is enacted, or December 22, 2017 for the Tax Act. ASC 740 also requires deferred tax assets and liabilities to be measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. The Company re-measured its deferred tax assets and liabilities at the 21% federal corporate tax rate, reevaluated its investments in affordable housing projects using the 21% federal corporate tax rate, and reduced its deferred tax assets associated with executive compensation that is no longer deductible.
Federal	$ 12,900
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount		$ 700
Increase (Decrease) in Deferred Income Taxes		26,400
Deferred Income Tax Expense (Benefit)		22,845	$ 2,777	$ (4,575)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		11,800
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	900	900	800	800
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		0	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 0	0	0	0
Internal Revenue Service (IRS) [Member]
Income Tax Expense Components [Line Items]
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount				1,200
State and Local Jurisdiction [Member]
Income Tax Expense Components [Line Items]
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount				200
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount				500
Income Tax Expense Components, Continuing Operations [Member]
Income Tax Expense Components [Line Items]
Federal		17,176	20,237	25,631
Deferred Income Tax Expense (Benefit)		$ 22,511	$ 2,948	$ (4,422)

Income Taxes Text Details (Deta

Income Taxes Text Details (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Statutory Federal income tax rate	35.00%	35.00%	35.00%
Increase (Decrease) in Deferred Income Taxes	$ 26,400
Deferred Income Tax Expense (Benefit)	22,845	$ 2,777	$ (4,575)
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	900	800	800
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0	0
Income Tax Expense Components, Continuing Operations [Member]
Tax Credit Carryforward [Line Items]
Deferred Income Tax Expense (Benefit)	22,511	$ 2,948	$ (4,422)
Discontinued Operations [Member]
Tax Credit Carryforward [Line Items]
Deferred Income Tax Expense (Benefit)	300
Shareholders' Equity [Member]
Tax Credit Carryforward [Line Items]
Increase (Decrease) in Deferred Income Taxes	$ 3,600

Employee Benefits 401(k) Plan (

Employee Benefits 401(k) Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
EMPLOYEE BENEFITS [Abstract]
Defined Contribution Plan, Cost	$ 3.3	$ 3	$ 2.8

Employee Benefits Salary Contin

Employee Benefits Salary Continuation Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
San Francisco Salary Continuation Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Postemployment Benefits, Period Expense	$ 0.1	$ 0.1	$ 0.1
Postemployment Benefits Liability	1	1.1
Cash Surrender Value of Life Insurance	6.1	6.3
Southern California Salary Continuation Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Postemployment Benefits, Period Expense	0.1	0.1	$ 0.1
Postemployment Benefits Liability	1.7	1.9
Cash Surrender Value of Life Insurance	$ 4.9	$ 4.8

Employee Benefits Deferred Comp

Employee Benefits Deferred Compensation Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred Compensation Liability, Current and Noncurrent	$ 7.1	$ 6.1
Deferred Compensation Arrangement with Individual, Compensation Expense	0.9	0.6	$ (0.1)
Deferred Compensation Plan Assets	7.1	6.1
Deferred Compensation Plan Assets, Income	$ 0.9	$ 0.6	$ (0.1)

Employee Benefits Stock Based I

Employee Benefits Stock Based Incentive Plans (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
2009 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,414,842
2010 Inducement Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,245,000
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	The terms of the Inducement Plan are substantially similar to the terms of the 2009 Plan.
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	24,569	37,177	22,936
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	727,491
Employee Stock Purchase Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	Under the ESPP, eligible employees may purchase common stock of the Company at 85 percent of the lower of the closing price of the Company’s common stock on the first or last day of a six month purchase period on The NASDAQ® Global Select Market. Employees pay for their stock purchases through payroll deductions at a rate equal to any whole percentage from 1 percent to 15 percent of after-tax earnings.
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	140,284
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	637,442
Stock Options [Member] | 2009 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	Generally, options expire ten years from the date granted and vest over a three-year graded vesting period for officers and employees and a one-year or less period for non-employee directors.
Restricted Stock [Member] | 2009 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award	Stock grants generally vest over a three-year cliff vesting period

Employee Benefits Share based p

Employee Benefits Share based payments in compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock or Unit Option Plan Expense	$ 480	$ 437	$ 518
Restricted Stock or Unit Expense	7,794	6,293	5,723
Allocated Share-based Compensation Expense	8,274	6,730	6,241
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	3,188	2,574	2,367
Allocated Share-based Compensation Expense, Net of Tax	$ 5,086	$ 4,156	$ 3,874

Employee Benefits Stock Options

Employee Benefits Stock Options Shares Rollforward (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Beginning of Period	656,400
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Beginning of Period	$ 13.11
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	109,400
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 8.21
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	12,798
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price	$ 28.85
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period	115,547
Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price	$ 29.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number End of Period	418,655	656,400
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price End of Period	$ 9.32	$ 13.11
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	1 year 9 months 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 2,795,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	418,655
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 9.32
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	1 year 9 months 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 2,795,000
2009 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	900,000	$ 1,500,000	$ 700,000
2009 Stock Option and Incentive Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options	$ 0

Employee Benefits Restricted St

Employee Benefits Restricted Stock Share Rollforward (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	2 years 3 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Beginning of Period	1,993,628
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	485,263
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	652,193
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	100,789
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number End of Period	1,725,909	1,993,628
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Beginning of Period	$ 12.16
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	15.55	$ 11.58	$ 12.41
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	12.28
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	13.35
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value End of Period	$ 13.03	$ 12.16
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 10.8
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Total Fair Value	$ 8	$ 5.3	$ 5.3
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number End of Period	811,286
Potential performance shares, incremental expense	$ 9.8
Potential Incremental Performance Shares Outstanding	747,125
Maximum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number End of Period	1,558,411

Employee Benefits Supplemental

Employee Benefits Supplemental Executive Retirement Plans and Long Term Incentive Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 0.9	$ 0.6	$ (0.1)
Holding Company SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	7.9	8.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 0.4	$ 0.5	$ 0.5
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.60%	4.10%	4.35%
Pacific Northwest SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	$ 3.2	$ 3.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		$ 0.2	$ 0.2
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.37%	3.62%	3.81%
KLS LTIP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	$ 8.1	$ 7.6
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 0.5	$ (0.2)	$ 1.3
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.33%	3.70%	3.90%

Other Operating Expense (Detail

Other Operating Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
other operating expense components [Line Items]
Travel and Entertainment Expense	$ 3,910	$ 3,309	$ 2,874
General Insurance Expense	3,286	3,396	3,518
Other Banking Expense	1,541	1,035	1,788
Publications and Dues expense	1,028	984	870
Postage Expense	974	967	1,007
Supplies Expense	890	836	1,241
Foreclosed Real Estate Expense	4	227	197
Valuation Allowances and Reserves, Deductions	(24)	(367)	(271)
Other Cost and Expense, Operating	2,960	3,050	3,337
Other Noninterest Expense	$ 14,569	$ 13,437	$ 14,561

Reportable Segments (Details)

Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016		Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Net interest income		$ 57,272	[1]	$ 56,627		$ 57,145		$ 53,642		$ 51,519	[1]	$ 49,871		$ 49,169		$ 49,879		$ 224,686		$ 200,438		$ 185,770
Fees and other income		39,175	[1]	40,267		38,018		36,506		43,958	[1]	40,012		36,795		38,022		153,966		158,787		161,169
Total revenues																		378,652		359,225		346,939
Provision/ (credit) for loan losses		(942)	[1]	(432)		(6,114)		(181)		(1,128)	[1]	(138)		(2,535)		(3,133)		(7,669)		(6,935)		(1,555)
Operating expense		93,989	[1]	69,346		67,821		68,780		71,843	[1]	61,670		64,731		66,709		299,936		264,953		255,181
Income/ (loss) before income taxes		3,400	[1]	27,980		33,456		21,549		24,762	[1]	28,351		23,768		24,325		86,385		101,207		93,313
Income tax expense/(benefit)		21,391	[1]	8,289		9,963		6,553		7,247	[1]	8,652		7,626		7,438		46,196	[2]	30,963	[2]	30,392	[2]
Net income from continuing operations																		40,189		70,244		62,921
Net Income (Loss) Attributable to Noncontrolling Interest		1,278	[1]	1,074		1,150		966		1,147	[1]	1,110		989		911		4,468		4,157		4,407
Income from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		989	[1]	1,186		1,063		1,632		1,184	[1]	1,047		1,245		2,065		4,870	[3]	5,541	[3]	6,411	[3]
Net income attributable to the Company		(18,280)	[1]	$ 19,803		$ 23,406		$ 15,662		17,552	[1]	$ 19,636		$ 16,398		$ 18,041		40,591		71,628		64,925
Assets		8,311,744								7,970,474								8,311,744		7,970,474		7,542,508
Amortization of Intangible Assets																		5,601		6,282		6,711
Depreciation																		8,106		6,838		6,590
Private Banking Segment [Member]
Segment Reporting Information [Line Items]
Net interest income																		227,280		202,702		189,501
Fees and other income																		10,856		18,947		11,352
Total revenues																		238,136		221,649		200,853
Provision/ (credit) for loan losses																		(7,669)		(6,935)		(1,555)
Operating expense																		149,008		125,116		116,575
Income/ (loss) before income taxes																		96,797		103,468		85,833
Income tax expense/(benefit)	[2]																	43,356		33,120		27,844
Net income from continuing operations																		53,441		70,348		57,989
Net income attributable to the Company																		53,441		70,348		57,989
Assets		8,177,304								7,816,671								8,177,304		7,816,671		7,361,202
Amortization of Intangible Assets																		0		0		341
Depreciation																		5,639		4,477		4,599
Wealth Management and Trust Segment [Member]
Segment Reporting Information [Line Items]
Fees and other income																		45,813		44,401		53,336
Operating expense	[4]																	49,287		64,844		54,474
Income/ (loss) before income taxes																		(3,474)		(20,443)		(1,138)
Income tax expense/(benefit)	[2]																	(509)		(8,279)		(350)
Net income from continuing operations																		(2,965)		(12,164)		(788)
Net income attributable to the Company																		(2,965)		(12,164)		(788)
Assets		74,128								80,501								74,128		80,501		80,088
Amortization of Intangible Assets																		2,882		2,962		2,428
Depreciation																		1,331		1,145		772
Investment Managers Segment [Member]
Segment Reporting Information [Line Items]
Net interest income																		21		16		22
Fees and other income																		45,551		44,443		45,687
Total revenues																		45,572		44,459		45,709
Operating expense	[5]																	59,032		32,863		33,690
Income/ (loss) before income taxes																		(13,460)		11,596		12,019
Income tax expense/(benefit)	[2]																	3,811		3,789		3,956
Net income from continuing operations																		(17,271)		7,807		8,063
Net Income (Loss) Attributable to Noncontrolling Interest																		1,973		2,077		2,265
Net income attributable to the Company																		(19,244)		5,730		5,798
Assets		66,614								92,692								66,614		92,692		92,642
Amortization of Intangible Assets																		2,524		2,601		2,956
Depreciation																		248		284		286
Wealth Advisors Segment [Member]
Segment Reporting Information [Line Items]
Net interest income																		124		16		6
Fees and other income																		52,636		50,686		50,558
Total revenues																		52,760		50,702		50,564
Operating expense																		35,753		34,791		35,379
Income/ (loss) before income taxes																		17,007		15,911		15,185
Income tax expense/(benefit)	[2]																	6,418		6,084		5,819
Net income from continuing operations																		10,589		9,827		9,366
Net Income (Loss) Attributable to Noncontrolling Interest																		2,495		2,080		2,138
Net income attributable to the Company																		8,094		7,747		7,228
Assets		77,747								79,887								77,747		79,887		79,543
Amortization of Intangible Assets																		195		719		986
Depreciation																		888		878		864
Holding Company and Eliminations Segment [Member]
Segment Reporting Information [Line Items]
Net interest income																		(2,739)		(2,296)		(3,759)
Fees and other income	[6]																	(890)		310		236
Total revenues																		(3,629)		(1,986)		(3,523)
Operating expense																		6,856		7,339		15,063
Income/ (loss) before income taxes																		(10,485)		(9,325)		(18,586)
Income tax expense/(benefit)	[2]																	(6,880)		(3,751)		(6,877)
Net income from continuing operations																		(3,605)		(5,574)		(11,709)
Net Income (Loss) Attributable to Noncontrolling Interest																		0		0		4
Income from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	[3]																	4,870		5,541		6,411
Net income attributable to the Company																		1,265		(33)		(5,302)
Assets		$ (84,049)								$ (99,277)								(84,049)		(99,277)		(70,967)
Depreciation																		$ 0		$ 54		$ 69
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.
[3]	The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively
[4]	Operating expense related to the Wealth Management and Trust segment includes restructuring expenses of $2.0 million, and $3.7 million for the years ending December 31, 2016 and 2015 respectively, and a goodwill impairment charge of $9.5 million for the year ended December 31, 2016.
[5]	Operating expense related to the Investment Management Segment includes a goodwill impairment charge of $24.9 million for the year ended December 31, 2017.
[6]	Fees and other income for the Holding Company includes a loss on the sale of $1.3 million for the year ended December 31, 2017 related to the classification of Anchor as held for sale.

Reportable Segments Segments Te

Reportable Segments Segments Text Disclosures (Details) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2017USD ($)

[1]

Sep. 30, 2017USD ($)

[1]

Jun. 30, 2017USD ($)

[1]

Mar. 31, 2017USD ($)

[1]

Dec. 31, 2016USD ($)

[1]

Sep. 30, 2016USD ($)

[1]

Jun. 30, 2016USD ($)

[1]

Mar. 31, 2016USD ($)

[1]

Dec. 31, 2017USD ($)segments

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Segment Reporting Information [Line Items]

Number of Reportable Segments | segments

4

Restructuring expense

$ 0

$ 2,017

$ 3,724

Impairment of goodwill

24,901

9,528

0

Gain/ (loss) on sale of affiliates or offices

(1,264)

2,862

0

Income from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest

$ 989

$ 1,186

$ 1,063

$ 1,632

$ 1,184

$ 1,047

$ 1,245

$ 2,065

4,870

[2]

5,541

[2]

6,411

[2]

Wealth Management and Trust Segment [Member]

Segment Reporting Information [Line Items]

Restructuring expense

2,017

3,724

Impairment of goodwill

0

9,528

Investment Managers Segment [Member]

Segment Reporting Information [Line Items]

Impairment of goodwill

24,901

[3]

0

Holding Company and Eliminations Segment [Member]

Segment Reporting Information [Line Items]

Gain/ (loss) on sale of affiliates or offices

1,300

Income from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest

[2]

$ 4,870

$ 5,541

$ 6,411

[1]

Due to rounding, the sum of the four quarters may not add to the year to date total.

[2]

The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively

[3]

Remaining goodwill of Anchor is classified as held for sale as of December 31, 2017.

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Recurring Basis (Details) - USD ($)	Dec. 31, 2017		Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 1,170,328,000		$ 1,264,132,000
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	0		0
Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount	0		0
U.S. government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	34,299,000	[1]	39,936,000
Government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	302,501,000	[1]	336,664,000
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	303,058,000	[1]	293,397,000
Mortgage-backed securities (1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	509,676,000	[2]	570,327,000	[3]
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	20,794,000	[4]	23,808,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	0		0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,170,328,000		1,264,132,000
Alternative Investment, Fair Value Disclosure	7,062,000		6,110,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	7,062,000		6,110,000
Fair Value, Measurements, Recurring [Member] | U.S. government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	34,299,000		39,936,000
Fair Value, Measurements, Recurring [Member] | Government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	302,501,000		336,664,000
Fair Value, Measurements, Recurring [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	303,058,000		293,397,000
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities (1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	509,676,000		570,327,000
Fair Value, Measurements, Recurring [Member] | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	20,794,000		23,808,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	54,890,000		63,101,000
Alternative Investment, Fair Value Disclosure	7,062,000		6,110,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	7,062,000		6,110,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	34,096,000		39,293,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-backed securities (1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	20,794,000		23,808,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,115,438,000		1,201,031,000
Alternative Investment, Fair Value Disclosure	0		0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	203,000		643,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	302,501,000		336,664,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	303,058,000		293,397,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-backed securities (1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	509,676,000		570,327,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Alternative Investment, Fair Value Disclosure	0		0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government and agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-backed securities (1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0		0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	18,575,000		17,032,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	18,953,000		16,560,000
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	18,575,000		17,032,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	18,953,000		16,560,000
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Loan Participations and Assignments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	1,000		15,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	108,000		6,000
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Loan Participations and Assignments [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Loan Participations and Assignments [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	1,000		15,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	108,000		6,000
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Loan Participations and Assignments [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	2,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	2,000
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	2,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	2,000
Fair Value, Measurements, Recurring [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	555,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	80,000		1,040,000
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	555,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	80,000		1,040,000
Fair Value, Measurements, Recurring [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	$ 0		$ 0
[1]	Certain securities are callable before their final maturity.
[2]	Mortgage-backed securities are shown based on their final (contractual) maturity, but, due to prepayments, they are expected to have shorter lives.
[3]	All mortgage-backed securities are guaranteed by U.S. government agencies or Government-sponsored entities.
[4]	Other securities consist of money market mutual funds and equity securities held by certain Wealth Advisory and Investment Management businesses.

Fair Value Measurements Fair132

Fair Value Measurements Fair Value Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands		Dec. 31, 2017		Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		$ 1,778	[1]	$ 3,074	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			1,690
Assets, Fair Value Disclosure		43,832		39,541
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		0	[1]	0	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			0
Assets, Fair Value Disclosure		0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		0	[1]	0	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			0
Assets, Fair Value Disclosure		0		0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		1,778	[1]	3,074	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			1,690
Assets, Fair Value Disclosure		43,832		39,541
Portion at Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		6,388,297		6,021,611
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		0		0
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		0		0
Portion at Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		6,388,297		6,021,611
Changes Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Receivable, Fair Value Disclosure		(465)	[1]	(428)	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			(110)
Assets, Fair Value Disclosure		(25,366)		(10,066)
Boston Private Wealth [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[4]			34,777
Boston Private Wealth [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[4]			0
Boston Private Wealth [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[4]			0
Boston Private Wealth [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[4]			34,777
Boston Private Wealth [Member] | Changes Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[4]			$ (9,528)
Anchor [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[5]	42,054
Anchor [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[5]	0
Anchor [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[5]	0
Anchor [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[5]	42,054
Anchor [Member] | Changes Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Fair Value Disclosure	[5]	$ (24,901)
[1]	Collateral-dependent impaired loans held as of December 31, 2017 that had write-downs in fair value or whose specific reserve changed during 2017.
[2]	Collateral-dependent impaired loans held as of December 31, 2016 that had write-downs in fair value or whose specific reserve changed during 2016
[3]	OREO held as of December 31, 2016 that had write-downs in fair value during 2016.
[4]	Goodwill balance at Boston Private Wealth as of December 31, 2016 that had write-downs in fair value during 2016. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for further detail.
[5]	Goodwill balance at Anchor as of December 31, 2017 that had write-downs in fair value during 2017. The goodwill balance related to Anchor is recorded in other assets held for sale as of December 31, 2017. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 8: Goodwill and Other Intangible Assets” for further detail. As of December 31, 2016 Fair value measurements at reporting date using: Gain (losses) from fair value changesQuoted prices in active marketsfor identicalassets (Level 1) Significant otherobservableinputs (Level 2) Significantunobservableinputs (Level 3) Year ended December 31, 2016(In thousands)Assets: Impaired loans (1)$3,074 $— $— $3,074 $(428)OREO (2)1,690 — — 1,690 (110)Goodwill (3)34,777 — — 34,777 (9,528) $39,541 $— $— $39,541 $(10,066)

Fair Value Measurements Quantit

Fair Value Measurements Quantitative Information about Level 3 Nonrecurring Assets (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure		$ 1,778	[1]	$ 3,074	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			1,690
Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure		$ 1,778	[1]	3,074	[2]
Other Real Estate Owned, Fair Value Disclosure	[3]			$ 1,690
Loans Receivable [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate		0.00%		5.00%
Fair Value Inputs, Comparability Adjustments		0.00%		0.00%
Loans Receivable [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate		7.00%		7.00%
Fair Value Inputs, Comparability Adjustments		20.00%		20.00%
Loans Receivable [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate		5.00%		6.00%
Fair Value Inputs, Comparability Adjustments		14.00%		13.00%
Other Assets [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate				0.00%
Fair Value Inputs, Comparability Adjustments				0.00%
Other Assets [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate				6.00%
Fair Value Inputs, Comparability Adjustments				18.00%
Other Assets [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate				6.00%
Fair Value Inputs, Comparability Adjustments				18.00%
Substandard [Member] | Market Approach Valuation Technique [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Loans Receivable, Fair Value Disclosure		$ 1,778		$ 3,074
Other Real Estate Owned, Fair Value Disclosure				$ 1,690
[1]	Collateral-dependent impaired loans held as of December 31, 2017 that had write-downs in fair value or whose specific reserve changed during 2017.
[2]	Collateral-dependent impaired loans held as of December 31, 2016 that had write-downs in fair value or whose specific reserve changed during 2016
[3]	OREO held as of December 31, 2016 that had write-downs in fair value during 2016.

Fair Value Measurements Not Mea

Fair Value Measurements Not Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017		Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	$ 73,781		$ 92,604
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	1,778	[1]	3,074	[2]
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	0	[1]	0	[2]
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	0	[1]	0	[2]
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	1,778	[1]	3,074	[2]
Portion at Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	120,541		106,557
Held-to-maturity Securities, Fair Value	73,781		92,604
Loans Held-for-sale, Fair Value Disclosure	4,737		3,428
Loans Receivable, Fair Value Disclosure	6,388,297		6,021,611
Other Assets, Fair Value Disclosure	93,449		77,956
Deposits, Fair Value Disclosure	6,509,197		6,084,765
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	32,169		59,624
Federal Funds Purchased, Fair Value Disclosure	30,000		80,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	692,402		734,941
Subordinated Debt Obligations, Fair Value Disclosure	96,363		96,363
Other Liabilities, Fair Value Disclosure	2,224		1,942
Portion at Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	120,541		106,557
Held-to-maturity Securities, Fair Value	0		0
Loans Held-for-sale, Fair Value Disclosure	0		0
Loans Receivable, Fair Value Disclosure	0		0
Other Assets, Fair Value Disclosure	0		0
Deposits, Fair Value Disclosure	0		0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0		0
Federal Funds Purchased, Fair Value Disclosure	0		0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0		0
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Other Liabilities, Fair Value Disclosure	0		0
Portion at Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0		0
Held-to-maturity Securities, Fair Value	73,781		92,604
Loans Held-for-sale, Fair Value Disclosure	4,737		3,428
Loans Receivable, Fair Value Disclosure	0		0
Other Assets, Fair Value Disclosure	93,449		77,956
Deposits, Fair Value Disclosure	6,509,197		6,084,765
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	32,169		59,624
Federal Funds Purchased, Fair Value Disclosure	30,000		80,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	692,402		734,941
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Other Liabilities, Fair Value Disclosure	2,224		1,942
Portion at Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0		0
Held-to-maturity Securities, Fair Value	0		0
Loans Held-for-sale, Fair Value Disclosure	0		0
Loans Receivable, Fair Value Disclosure	6,388,297		6,021,611
Other Assets, Fair Value Disclosure	0		0
Deposits, Fair Value Disclosure	0		0
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0		0
Federal Funds Purchased, Fair Value Disclosure	0		0
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0		0
Subordinated Debt Obligations, Fair Value Disclosure	96,363		96,363
Other Liabilities, Fair Value Disclosure	0		0
Reported Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	120,541		106,557
Held-to-maturity Securities, Fair Value	74,576		93,079
Loans Held-for-sale, Fair Value Disclosure	4,697		3,464
Loans Receivable, Fair Value Disclosure	6,430,286		6,036,277
Other Assets, Fair Value Disclosure	93,449		77,956
Deposits, Fair Value Disclosure	6,510,246		6,085,146
Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	32,169		59,624
Federal Funds Purchased, Fair Value Disclosure	30,000		80,000
Federal Home Loan Bank Borrowings, Fair Value Disclosure	693,681		734,205
Subordinated Debt Obligations, Fair Value Disclosure	106,363		106,363
Other Liabilities, Fair Value Disclosure	$ 2,224		$ 1,942
[1]	Collateral-dependent impaired loans held as of December 31, 2017 that had write-downs in fair value or whose specific reserve changed during 2017.
[2]	Collateral-dependent impaired loans held as of December 31, 2016 that had write-downs in fair value or whose specific reserve changed during 2016

Financial Instruments With O135

Financial Instruments With Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Variable rate
Supply Commitment [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	$ 56,410	$ 103,189
Fixed rate
Supply Commitment [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	79,784	65,563
Total commitments to originate new loans
Supply Commitment [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	136,194	168,752
Unadvanced portion of loans and unused lines of credit
Supply Commitment [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	1,327,140	1,280,648
Standby letters of credit
Supply Commitment [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	46,291	38,391
Forward commitments to sell loans
Supply Commitment [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	$ 16,886	$ 9,663

Boston Private Financial Hol136

Boston Private Financial Holdings, Inc. (Parent Company Only) Balance Sheet (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents		$ 120,541	$ 106,557	$ 238,694	$ 172,609
Deferred income taxes, net		44,073	73,010
Other assets		259,515	130,753
Assets		8,311,744	7,970,474	7,542,508
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust		106,363	106,363
Deferred Income Tax Liabilities, Net		5,322	8,638
Other liabilities		135,880	119,683
Total liabilities		7,508,339	7,185,021
Stockholders' Equity Attributable to Noncontrolling Interest		22,647	21,133
Stockholders' Equity Attributable to Parent		780,758	764,320
Total liabilities, redeemable noncontrolling interests and shareholders’ equity		8,311,744	7,970,474
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents		66,361	54,694	$ 55,385	$ 44,593
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures		6,340	6,340
Other assets		11,046	17,131
Assets		926,418	909,944
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust		106,363	106,363
Other liabilities		11,328	9,490
Total liabilities		123,013	124,491
Stockholders' Equity Attributable to Noncontrolling Interest	[1]	22,647	21,133
Stockholders' Equity Attributable to Parent		780,758	764,320
Total liabilities, redeemable noncontrolling interests and shareholders’ equity		926,418	909,944
Parent Company [Member] | Private Banking Segment [Member]
Condensed Financial Statements, Captions [Line Items]
Investments in and Advances to Affiliates, Balance, Principal Amount		731,907	694,517
Parent Company [Member] | Non Banking Segments [Member]
Condensed Financial Statements, Captions [Line Items]
Investments in and Advances to Affiliates, Balance, Principal Amount		$ 110,764	$ 137,262
[1]	Includes noncontrolling interests and the maximum redemption value of redeemable noncontrolling interests.

Boston Private Financial Hol137

Boston Private Financial Holdings, Inc. (Parent Company Only) Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017	[1]	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Noninterest Income, Other Operating Income																	$ 2,098		$ 3,410		$ 3,722
Revenues																	378,652		359,225		346,939
Salaries and employee benefits																	178,406		163,767		159,401
Professional services																	13,763		11,576		12,861
Interest Expense, Junior Subordinated Debentures																	2,919		2,427		3,875
Other																	14,569		13,437		14,561
Income before income taxes	$ 3,400		$ 27,980		$ 33,456		$ 21,549		$ 24,762		$ 28,351		$ 23,768		$ 24,325		86,385		101,207		93,313
Income tax benefit	21,391		8,289		9,963		6,553		7,247		8,652		7,626		7,438		46,196	[2]	30,963	[2]	30,392	[2]
Income from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	989		1,186		1,063		1,632		1,184		1,047		1,245		2,065		4,870	[3]	5,541	[3]	6,411	[3]
Net income attributable to the Company	$ (18,280)		$ 19,803		$ 23,406		$ 15,662		$ 17,552		$ 19,636		$ 16,398		$ 18,041		40,591		71,628		64,925
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Interest Income, Operating																	180		130		116
Noninterest Income, Other Operating Income																	(1,071)		310		236
Revenues																	48,425		47,184		51,841
Salaries and employee benefits																	4,061		4,620		10,320
Professional services																	1,369		1,337		2,007
Interest Expense, Junior Subordinated Debentures																	2,919		2,427		3,875
Other																	1,424		1,381		2,740
Operating Expenses																	9,773		9,765		18,942
Income before income taxes																	38,652		37,419		32,899
Income tax benefit																	(6,880)		(3,751)		(6,877)
Income from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest																	4,870		5,541		6,411
Net income attributable to the Company																	50,402		46,711		46,187
Parent Company [Member] | Private Banking Segment [Member]
Condensed Financial Statements, Captions [Line Items]
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries																	25,200		22,700		22,700
Net income attributable to the Company																	(50,476)		(58,184)		(57,201)
Parent Company [Member] | Non Banking Segments [Member]
Condensed Financial Statements, Captions [Line Items]
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries																	24,116		24,044		28,789
Net income attributable to the Company																	11,150		(13,477)		(13,026)
Private Banking, Wealth Management and Trust, Investment Management, and Wealth Advisory Segments [Member] | Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net income attributable to the Company																	$ (9,811)		$ 24,917		$ 18,738
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.
[3]	The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively

Boston Private Financial Hol138

Boston Private Financial Holdings, Inc. (Parent Company Only) Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Net Income Attributable to Parent	$ (18,280)	[1]	$ 19,803		$ 23,406		$ 15,662	[1]	$ 17,552	[1]	$ 19,636		$ 16,398		$ 18,041	[1]	$ 40,591		$ 71,628		$ 64,925
Net income from discontinued operations	989	[1]	$ 1,186		$ 1,063		1,632	[1]	1,184	[1]	$ 1,047		$ 1,245		2,065	[1]	4,870	[2]	5,541	[2]	6,411	[2]
Net income from continuing operations																	40,189		70,244		62,921
Deferred income tax expense/ (benefit)																	22,845		2,777		(4,575)
Depreciation and amortization																	21,023		23,441		22,187
Net decrease/(increase) in other operating activities																	(8,466)		(817)		2,852
Net Cash Provided by (Used in) Operating Activities, Continuing Operations																	97,115		100,606		87,477
Cash Provided by (Used in) Operating Activities, Discontinued Operations																	4,870		5,541		6,411
Net Cash Provided by (Used in) Operating Activities																	101,985		106,147		93,888
Net Cash Provided by (Used in) Investing Activities																	(354,315)		(692,780)		(694,790)
Repurchase of common stock																	0		(9,323)		0
Dividends paid to common shareholders																	(37,054)		(33,110)		(29,608)
Dividends paid to preferred shareholders																	(3,475)		(3,475)		(3,475)
Tax savings/ (deficiency) from certain stock compensation awards																	0		(620)		(1,262)
Proceeds from stock option exercises																	882		1,725		1,206
Proceeds from issuance of common stock, net																	171		842		(515)
Other equity adjustments																	26		(82)		(199)
Net Cash Provided by (Used in) Financing Activities																	266,314		454,496		666,987
Cash and Cash Equivalents, Period Increase (Decrease)																	13,984		(132,137)		66,085
Cash and cash equivalents at beginning of year							106,557								238,694		106,557		238,694		172,609
Cash and cash equivalents at end of period	120,541								106,557								120,541		106,557		238,694
Parent Company [Member]
Net Income Attributable to Parent																	50,402		46,711		46,187
Net income from discontinued operations																	4,870		5,541		6,411
Net income from continuing operations																	35,721		66,087		58,514
Deferred income tax expense/ (benefit)																	(3,075)		10,000		(4,575)
Depreciation and amortization																	3,553		(738)		5,097
Net decrease/(increase) in other operating activities																	1,899		(16,633)		2,167
Net Cash Provided by (Used in) Operating Activities, Continuing Operations																	48,088		33,799		42,465
Cash Provided by (Used in) Operating Activities, Discontinued Operations																	4,870		5,541		6,411
Net Cash Provided by (Used in) Operating Activities																	52,958		39,340		48,876
Payments to Acquire Businesses, Net of Cash Acquired																	1,410		1,890		1,821
Payments for (Proceeds from) Other Investing Activities																	0		1		1
Net Cash Provided by (Used in) Investing Activities																	1,356		671		99
Repurchase of common stock																	0		9,323		0
Dividends paid to common shareholders																	(37,054)		(33,110)		(29,608)
Dividends paid to preferred shareholders																	(3,475)		(3,475)		(3,475)
Tax savings/ (deficiency) from certain stock compensation awards																	0		(620)		(1,262)
Proceeds from stock option exercises																	882		1,725		1,206
Proceeds from issuance of common stock, net																	2,740		7,786		160
Other equity adjustments																	(5,740)		(3,685)		(5,204)
Net Cash Provided by (Used in) Financing Activities																	(42,647)		(40,702)		(38,183)
Cash and Cash Equivalents, Period Increase (Decrease)																	11,667		(691)		10,792
Cash and cash equivalents at beginning of year							$ 54,694								$ 55,385		54,694		55,385		44,593
Cash and cash equivalents at end of period	$ 66,361								$ 54,694								66,361		54,694		55,385
Private Banking Segment [Member] | Parent Company [Member]
Net Income Attributable to Parent																	(50,476)		(58,184)		(57,201)
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries																	25,200		22,700		22,700
Non Banking Segments [Member] | Parent Company [Member]
Net Income Attributable to Parent																	11,150		(13,477)		(13,026)
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries																	24,116		24,044		28,789
Private Banking Segment [Member]
Net Income Attributable to Parent																	53,441		70,348		57,989
Net income from continuing operations																	53,441		70,348		57,989
Private Banking Segment [Member] | Parent Company [Member]
Payments of Distributions to Affiliates																	0		0		0
Non Banking Segments [Member] | Parent Company [Member]
Payments of Distributions to Affiliates																	$ (54)		$ (1,220)		$ (1,723)
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively

Regulatory Matters (Details)

Regulatory Matters (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital		$ 607,800	$ 571,663
Common Equity Tier One Capital Ratio		10.32%	10.00%
Common Equity Tier One Capital Required for Capital Adequacy		$ 265,153	$ 257,222
Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets		4.50%	4.50%
Tier One Risk Based Capital		$ 758,089	$ 722,674
Tier One Risk Based Capital to Risk Weighted Assets		12.87%	12.64%
Tier One Risk Based Capital Required for Capital Adequacy		$ 353,537	$ 342,962
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets		6.00%	6.00%
Capital		$ 832,182	$ 794,584
Capital to Risk Weighted Assets		14.12%	13.90%
Capital Required for Capital Adequacy		$ 471,383	$ 457,283
Capital Required for Capital Adequacy to Risk Weighted Assets		8.00%	8.00%
Tier One Leverage Capital		$ 758,089	$ 722,674
Tier One Leverage Capital to Average Assets		9.34%	9.42%
Tier One Leverage Capital Required for Capital Adequacy		$ 324,725	$ 306,848
Tier One Leverage Capital Required for Capital Adequacy to Average Assets		4.00%	4.00%
Basel III Minimum with Capital Conservation Buffer [Domain]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets	[1]	7.00%	7.00%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	[1]	8.50%	8.50%
Capital Required for Capital Adequacy to Risk Weighted Assets	[1]	10.50%	10.50%
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	[1]	4.00%	4.00%
Boston Private Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital		$ 694,201	$ 661,991
Common Equity Tier One Capital Ratio		11.83%	11.64%
Common Equity Tier One Capital Required for Capital Adequacy		$ 264,028	$ 256,030
Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets		4.50%	4.50%
Common Equity Tier One Capital Required to be Well-Capitalized		$ 381,373	$ 369,822
Common Equity Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets		6.50%	6.50%
Tier One Risk Based Capital		$ 694,201	$ 661,991
Tier One Risk Based Capital to Risk Weighted Assets		11.83%	11.64%
Tier One Risk Based Capital Required for Capital Adequacy		$ 352,037	$ 341,374
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets		6.00%	6.00%
Tier One Risk Based Capital Required to be Well Capitalized		$ 469,382	$ 455,165
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets		8.00%	8.00%
Capital		$ 767,576	$ 733,214
Capital to Risk Weighted Assets		13.08%	12.89%
Capital Required for Capital Adequacy		$ 469,382	$ 455,165
Capital Required for Capital Adequacy to Risk Weighted Assets		8.00%	8.00%
Capital Required to be Well Capitalized		$ 586,728	$ 568,956
Capital Required to be Well Capitalized to Risk Weighted Assets		10.00%	10.00%
Tier One Leverage Capital		$ 694,201	$ 661,991
Tier One Leverage Capital to Average Assets		8.63%	8.70%
Tier One Leverage Capital Required for Capital Adequacy		$ 321,920	$ 304,510
Tier One Leverage Capital Required for Capital Adequacy to Average Assets		4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized		$ 402,400	$ 380,637
Tier One Leverage Capital Required to be Well Capitalized to Average Assets		5.00%	5.00%
Boston Private Bank [Member] | Basel III Minimum with Capital Conservation Buffer [Domain]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets	[1]	7.00%	7.00%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	[1]	8.50%	8.50%
Capital Required for Capital Adequacy to Risk Weighted Assets	[1]	10.50%	10.50%
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	[1]	4.00%	4.00%
[1]	Required capital ratios under the Basel III capital rules with the fully phased-in capital conservation buffer added to the minimum risk-based capital ratios. The fully phased-in ratios are effective for 2019, with lower requirements during the transition years 2016 through 2018.

Regulatory Matters Text Details

Regulatory Matters Text Details (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Risk Based Capital	$ 758,089	$ 722,674
Junior Subordinated Debentures [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Risk Based Capital	$ 100,000	$ 100,000

Selected Quarterly Data (Una141

Selected Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Interest Income (Expense), Net		$ 57,272	[1]	$ 56,627	[1]	$ 57,145	[1]	$ 53,642	[1]	$ 51,519	[1]	$ 49,871	[1]	$ 49,169	[1]	$ 49,879	[1]	$ 224,686		$ 200,438		$ 185,770
Noninterest Income		39,175	[1]	40,267	[1]	38,018	[1]	36,506	[1]	43,958	[1]	40,012	[1]	36,795	[1]	38,022	[1]	153,966		158,787		161,169
Revenue, Net	[1]	96,447		96,894		95,163		90,148		95,477		89,883		85,964		87,901
Provision/ (credit) for loan losses		(942)	[1]	(432)	[1]	(6,114)	[1]	(181)	[1]	(1,128)	[1]	(138)	[1]	(2,535)	[1]	(3,133)	[1]	(7,669)		(6,935)		(1,555)
Noninterest Expense		93,989	[1]	69,346	[1]	67,821	[1]	68,780	[1]	71,843	[1]	61,670	[1]	64,731	[1]	66,709	[1]	299,936		264,953		255,181
Income before income taxes		3,400	[1]	27,980	[1]	33,456	[1]	21,549	[1]	24,762	[1]	28,351	[1]	23,768	[1]	24,325	[1]	86,385		101,207		93,313
Income tax expense		21,391	[1]	8,289	[1]	9,963	[1]	6,553	[1]	7,247	[1]	8,652	[1]	7,626	[1]	7,438	[1]	46,196	[2]	30,963	[2]	30,392	[2]
Net income from discontinued operations		989	[1]	1,186	[1]	1,063	[1]	1,632	[1]	1,184	[1]	1,047	[1]	1,245	[1]	2,065	[1]	4,870	[3]	5,541	[3]	6,411	[3]
Net Income (Loss) Attributable to Noncontrolling Interest		1,278	[1]	1,074	[1]	1,150	[1]	966	[1]	1,147	[1]	1,110	[1]	989	[1]	911	[1]	4,468		4,157		4,407
Net income attributable to the Company		$ (18,280)	[1]	$ 19,803	[1]	$ 23,406	[1]	$ 15,662	[1]	$ 17,552	[1]	$ 19,636	[1]	$ 16,398	[1]	$ 18,041	[1]	$ 40,591		$ 71,628		$ 64,925
Earnings (Loss) Per Share, Basic		$ (0.24)	[1],[4]	$ 0.23	[1],[4]	$ 0.28	[1],[4]	$ 0.18	[1],[4]	$ 0.19	[1],[4]	$ 0.23	[1],[4]	$ 0.19	[1],[4]	$ 0.22	[1],[4]	$ 0.43		$ 0.83		$ 0.77
Earnings/ (Loss) Per Share, Diluted		$ (0.24)	[1],[4]	$ 0.22	[1],[4]	$ 0.27	[1],[4]	$ 0.17	[1],[4]	$ 0.19	[1],[4]	$ 0.22	[1],[4]	$ 0.18	[1],[4]	$ 0.21	[1],[4]	$ 0.42		$ 0.81		$ 0.74
[1]	Due to rounding, the sum of the four quarters may not add to the year to date total.
[2]	The Company’s effective tax rate for 2017, 2016, and 2015 is not consistent due to the re-measurement of the deferred tax assets, impairment of goodwill not deductible for tax purposes, earnings from tax-exempt investments, non-deductible compensation, state and local taxes, income tax credits and income attributable to noncontrolling interests having a different impact on the effective tax rate due primarily to the different levels of income before taxes in years 2017, 2016, and 2015. See Part II. Item 8. “Financial Statements and Supplementary Data - Note 17: Income Taxes” for additional details.
[3]	The Holding Company and Eliminations calculation of Net Income attributable to the Company includes net income from Discontinued Operations for the years ended December 31, 2017, 2016 and 2015 of $4.9 million, $5.5 million, and $6.4 million, respectively
[4]	Includes the effect of adjustments to net income attributable to the Company to arrive at net income attributable to common shareholders.