Independent Bank (INDB) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 04, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Entity Information [Line Items]
Document Transition Report	false
Common Stock, Shares, Outstanding	32,955,547			34,377,388
City Area Code	(781)
Entity Incorporation, State or Country Code	MA
Entity File Number	1-9047
Document Quarterly Report	true
Entity Registrant Name	Independent Bank Corp.
Entity Tax Identification Number	04-2870273
Entity Central Index Key	0000776901
Document Type	10-Q
Document Period End Date	Sep. 30, 2020
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		32,965,121
Local Phone Number	878-6100
Entity Address, Address Line One	2036 Washington Street,
Entity Address, City or Town	Hanover,
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02339
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
NASDAQ/NGS (GLOBAL SELECT MARKET) [Member]
Entity Information [Line Items]
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	INDB
Common Class A [Member]
Entity Information [Line Items]
Common Stock, Shares, Outstanding	32,955,547		32,942,110	34,377,388	34,366,781	34,321,061	28,080,408
Mailing Address [Member]
Entity Information [Line Items]
Entity Address, Address Line One	288 Union Street,
Entity Address, City or Town	Rockland,
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02370

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Assets
Cash and due from banks	$ 125,103,000	$ 114,686,000
Interest-earning deposits with banks	1,142,934,000	36,288,000
Securities
Trading	2,612,000	2,179,000
Equity Securities, FV-NI	21,119,000	21,261,000
Debt Securities, Available-for-sale	423,478,000	426,424,000
Held to maturity (fair value $690,467 and $753,263)	659,573,000	740,806,000
Total securities	1,106,782,000	1,190,670,000
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	54,713,000	33,307,000
Loans
Total loans	9,405,193,000	8,873,639,000
Less: allowance for credit losses	(115,625,000)	(67,740,000)
Net loans	9,289,568,000	8,805,899,000
Federal Home Loan Bank stock	15,090,000	14,424,000
Bank premises and equipment, net	121,816,000	123,674,000
Goodwill	506,206,000	506,206,000
Other intangible assets	24,543,000	29,286,000
Cash surrender value of life insurance policies	199,453,000	197,372,000
Other assets	587,457,000	343,353,000
Total assets	13,173,665,000	11,395,165,000
Deposits
Noninterest-bearing demand deposits	3,715,528,000	2,662,591,000
Savings and interest checking accounts	3,912,703,000	3,232,909,000
Money market	2,164,436,000	1,856,552,000
Time certificates of deposit of $100,000 and over	570,068,000	663,645,000
Other time certificates of deposits	488,573,000	731,670,000
Total deposits	10,851,308,000	9,147,367,000
Borrowings
Federal Home Loan Bank borrowings	145,765,000	115,748,000
Long-term Debt	37,447,000	74,906,000
Junior Subordinated Notes	62,850,000	62,848,000
Subordinated debentures (less unamortized debt issuance costs of $328 and $399)	49,672,000	49,601,000
Total borrowings	295,734,000	303,103,000
Other liabilities	336,899,000	236,552,000
Total liabilities	11,483,941,000	9,687,022,000
Commitments and contingencies	$ 0	$ 0
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, Shares Authorized	$ 0.01	$ 0.01
Stockholders' equity
Preferred stock, $0.01 par value, authorized: 1,000,000 shares, outstanding: none	$ 0	$ 0
Common stock, $0.01 par value, authorized: 75,000,000 shares, issued and outstanding: 32,955,547 shares at September 30, 2020 and 34,377,388 shares at December 31, 2019 (includes 137,457 and 147,184 shares of unvested participating restricted stock awards, respectively)	328,000	342,000
Value of shares held in rabbi trust at cost: 135,111 shares at September 30, 2020 and 143,820 shares at December 31, 2019	(4,712,000)	(4,735,000)
Deferred compensation and other retirement benefit obligations	4,712,000	4,735,000
Additional paid in capital	944,218,000	1,035,450,000
Retained earnings	696,546,000	654,182,000
Accumulated other comprehensive income, net of tax	48,632,000	18,169,000
Total stockholders’ equity	1,689,724,000	1,708,143,000
Total liabilities and stockholders' equity	13,173,665,000	11,395,165,000
Interest-bearing Deposit Liabilities	100,000	100,000
Debt Securities, Held-to-maturity, Fair Value	690,467,000	753,263,000
Debt Securities, Available-for-sale, Amortized Cost	$ 404,159,000	$ 420,703,000
Shares Held in Rabbi Trust at Cost	135,111	143,820
Common Stock, Shares Authorized	75,000,000	75,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	137,457	147,184
Common Stock, Shares, Issued	32,955,547	34,377,388
Common Stock, Shares, Outstanding	32,955,547	34,377,388
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Class A [Member]
Stockholders' equity
Common Stock, Shares, Outstanding	32,955,547	34,377,388
Long-term Debt [Member]
Stockholders' equity
Unamortized Debt Issuance Expense	$ 53,000	$ 94,000
Subordinated Debt [Member]
Stockholders' equity
Unamortized Debt Issuance Expense	328,000	399,000
Junior Subordinated Debt [Member]
Stockholders' equity
Unamortized Debt Issuance Expense	38,000	40,000
Commercial And Industrial [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	2,062,345,000	1,395,036,000
Total loans	2,062,345,000	1,395,036,000
Less: allowance for credit losses	(17,332,000)
Commercial Real Estate [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	4,125,464,000	4,002,359,000
Total loans	4,125,464,000	4,002,359,000
Less: allowance for credit losses	(32,651,000)
Construction Loans [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	573,334,000	547,293,000
Total loans	573,334,000	547,293,000
Less: allowance for credit losses	(5,833,000)
Small Business [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	167,632,000	174,497,000
Total loans	167,632,000	174,497,000
Less: allowance for credit losses	(1,752,000)
Residential Real Estate [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	1,352,305,000	1,590,569,000
Total loans	1,352,305,000	1,590,569,000
Less: allowance for credit losses	(3,348,000)
Home Equity Loan [Member]
Loans
Total loans	1,101,054,000
Consumer Portfolio Segment [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	23,059,000	30,087,000
Total loans	23,059,000	30,087,000	[1]
Less: allowance for credit losses	(277,000)
Senior Lien [Member] | Home Equity Loan [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	643,187,000	649,255,000
Junior Lien [Member] | Home Equity Loan [Member]
Loans
Financing Receivable, before Allowance for Credit Loss	$ 457,867,000	$ 484,543,000
[1]	Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances.

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Time certificates of deposit least amount	$ 100,000	$ 100,000
Held to Maturity, Fair Value, Total	690,467,000	753,263,000
Debt Securities, Available-for-sale, Amortized Cost	$ 404,159,000	$ 420,703,000
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, shares outstanding	0	0
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	75,000,000	75,000,000
Common Stock, Shares, Outstanding	32,955,547	34,377,388
Common Stock, unvested restricted Stock awards	137,457	147,184
Shares Held in Rabbi Trust	135,111	143,820
Common Stock Outstanding
Common Stock, Shares, Outstanding	32,955,547	34,377,388
Subordinated Debt [Member]
Unamortized Debt Issuance Expense	$ 328,000	$ 399,000
Long-term Debt [Member]
Unamortized Debt Issuance Expense	$ 53,000	$ 94,000

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income
Interest and fees on loans	$ 90,112	$ 110,205	$ 280,768	$ 306,736
Interest Income, Securities, Operating, Taxable	7,218	8,269	23,006	24,255
Nontaxable interest and dividends on securities	9	14	27	40
Interest on loans held for sale	326	456	917	527
Interest on federal funds sold and short-term investments	254	680	546	1,753
Total interest and dividend income	97,919	119,624	305,264	333,311
Interest expense
Interest on deposits	5,432	11,846	23,351	30,052
Interest on borrowings	1,604	3,180	5,628	10,117
Total interest expense	7,036	15,026	28,979	40,169
Net interest income	90,883	104,598	276,285	293,142
Provision for credit losses	7,500	0	52,500	2,000
Net interest income after provision for credit losses	83,383	104,598	223,785	291,142
Noninterest income
Deposit account fees	3,428	5,299	11,227	14,785
Interchange and ATM fees	3,044	6,137	13,154	16,447
Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions	7,571	7,188	21,696	21,089
Mortgage banking income	7,704	3,968	13,570	8,184
Bank Owned Life Insurance Income	1,314	1,304	3,902	3,572
Gain Realized on Life Insurance Policies	0	(434)	(692)	(434)
Loan level derivative income	2,457	2,739	8,918	4,312
Other noninterest income	3,829	4,747	10,813	13,174
Total noninterest income	29,347	31,816	83,972	81,997
Noninterest expenses
Salaries and employee benefits	38,409	39,432	113,027	111,401
Occupancy and equipment expenses	9,273	8,555	27,863	24,109
Data processing & facilities management	1,567	1,515	4,684	4,883
FDIC assessment	1,034	0	1,537	1,394
Advertising expense	1,215	1,417	3,107	3,912
Professional Fees	1,305	1,338	4,244	3,486
Amortization of Intangible Assets	1,428	1,567	4,392	3,996
Available-for-Sale Securities - Fixed Income Gross Realized Losses	0	0	0	1,462
Loss on Contract Termination	684	0	684	0
Business Combination, Acquisition Related Costs	0	705	0	26,433
Software Maintenance	1,753	1,385	5,218	3,913
Other noninterest expenses	9,990	11,619	35,349	31,887
Total noninterest expenses	66,658	67,533	200,105	216,876
Income before income taxes	46,072	68,881	107,652	156,263
Current Federal, State and Local, Tax Expense (Benefit)	11,199	17,036	21,126	38,565
Net income	$ 34,873	$ 51,845	$ 86,526	$ 117,698
Basic earnings per share (in dollars per share)	$ 1.06	$ 1.51	$ 2.59	$ 3.65
Diluted earnings per share (in dollars per share)	$ 1.06	$ 1.51	$ 2.59	$ 3.64
Weighted average common shares (basic) (in shares)	32,951,918	34,361,176	33,358,879	32,283,196
Common shares equivalents (in shares)	24,758	39,390	27,871	45,416
Weighted average common shares (diluted) (in shares)	32,976,676	34,400,566	33,386,750	32,328,612
Retained Earnings [Member]
Noninterest expenses
Net income	$ 34,873	$ 51,845	$ 86,526	$ 117,698
Cash dividends declared per common share (in dollars per share)	$ 0.46	$ 0.44	$ 1.38	$ 1.32

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income		$ 34,873	$ 51,845	$ 86,526	$ 117,698
Other comprehensive income (loss), net of tax
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax		(709)	2,175	10,333	12,349
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax		(2,729)	3,030	20,452	14,905
Net change in other comprehensive income for defined benefit postretirement plans	[1]	225	41	(322)	121
Total other comprehensive income (loss)		(3,213)	5,246	30,463	27,375
Total comprehensive income		$ 31,660	$ 57,091	$ 116,989	$ 145,073
[1]	The following tables present a reconciliation of the changes in the components of other comprehensive income (loss) for the periods indicated, including the amount of income tax (expense) benefit allocated to each component of other comprehensive income (loss): Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (857) $ 148 $ (709) $ 13,598 $ (3,265) $ 10,333 Less: net security losses reclassified into other noninterest expense — — — — — — Net change in fair value of securities available for sale (857) 148 (709) 13,598 (3,265) 10,333 Change in fair value of cash flow hedges (143) 41 (102) 37,674 (10,597) 27,077 Less: net cash flow hedge gains reclassified into interest income or interest expense 4,339 (1,220) 3,119 9,901 (2,784) 7,117 Less: Loss on termination of hedge reclassified into noninterest expense (684) 192 (492) (684) 192 (492) Net change in fair value of cash flow hedges (3,798) 1,069 (2,729) 28,457 (8,005) 20,452 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (2) 1 (1) (1,392) 392 (1,000) Amortization of net actuarial losses 245 (69) 176 736 (207) 529 Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 312 (87) 225 (449) 127 (322) Total other comprehensive income (loss) $ (4,343) $ 1,130 $ (3,213) $ 41,606 $ (11,143) $ 30,463 Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ 2,858 $ (683) $ 2,175 $ 14,699 $ (3,401) $ 11,298 Less: net security losses reclassified into other noninterest expense — — — (1,462) 411 (1,051) Net change in fair value of securities available for sale 2,858 (683) 2,175 16,161 (3,812) 12,349 Change in fair value of cash flow hedges 4,568 (1,285) 3,283 21,913 (6,167) 15,746 Less: net cash flow hedge gains reclassified into interest income or interest expense 352 (99) 253 1,170 (329) 841 Net change in fair value of cash flow hedges 4,216 (1,186) 3,030 20,743 (5,838) 14,905 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (11) 3 (8) (33) 9 (24) Amortization of net actuarial gains (2) 1 (1) (6) 2 (4) Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 56 (15) 41 168 (47) 121 Total other comprehensive income $ 7,130 $ (1,884) $ 5,246 $ 37,072 $ (9,697) $ 27,375 (1) The amortization of prior service costs is included in the computation of net periodic pension cost as disclosed in the Employee Benefit Plans footnote in the Company's Annual Report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission.

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)		Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock Outstanding	Common Stock	Value of Shares Held in Rabbi Trust at Cost	Deferred Compensation and Other Retirement Benefit Obligations	Additional Paid in Capital	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income/(Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding				28,080,408
Net income		$ 117,698,000							$ 117,698,000
Other comprehensive income		27,375,000									$ 27,375,000
Cash dividends declared per common share (in dollars per share)									$ 1.32
Common dividend declared		(42,603,000)							$ (42,603,000)
Stock Issued During Period, Shares, Acquisitions				6,166,010
Stock Issued During Period, Value, Acquisitions		499,693,000			$ 61,000			$ 499,632,000
Proceeds from exercise of stock options, net of cash paid				11,000
Proceeds from exercise of stock options, net of cash paid		281,000			0			281,000
Stock based compensation		3,413,000						3,413,000
Restricted stock awards issued, net of awards surrendered				50,431
Restricted stock awards issued, net of awards surrendered		(1,435,000)			1,000			(1,436,000)
Shares issued under direct stock purchase plan				58,932
Shares issued under direct stock purchase plan		4,412,000			1,000			4,411,000
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits						$ 5,000	$ (5,000)
Increase (Decrease) in Deferred Compensation		0
Period End Balance at Sep. 30, 2019		1,682,324,000			342,000	(4,713,000)	4,713,000	1,033,949,000	621,831,000		26,202,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding				34,321,061
Net income		51,845,000							$ 51,845,000
Other comprehensive income		5,246,000									5,246,000
Cash dividends declared per common share (in dollars per share)									$ 0.44
Common dividend declared		(15,125,000)							$ (15,125,000)
Stock Issued During Period, Shares, Acquisitions				0
Stock Issued During Period, Value, Acquisitions		0			0			0
Proceeds from exercise of stock options, net of cash paid				0
Proceeds from exercise of stock options, net of cash paid		0			0			0
Stock based compensation		981,000						981,000
Restricted stock awards issued, net of awards surrendered				(43)
Restricted stock awards issued, net of awards surrendered		(4,000)			(1,000)			(3,000)
Shares issued under direct stock purchase plan				45,763
Shares issued under direct stock purchase plan		3,378,000			1,000			3,377,000
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits						(65,000)	65,000
Increase (Decrease) in Deferred Compensation		0
Period End Balance at Sep. 30, 2019		$ 1,682,324,000			342,000	(4,713,000)	4,713,000	1,033,949,000	621,831,000		26,202,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding				34,366,781
Common Stock, Shares, Outstanding		34,377,388		34,377,388
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		$ (1,137,000)
Net income		86,526,000							$ 86,526,000
Other comprehensive income		30,463,000									30,463,000
Cash dividends declared per common share (in dollars per share)									$ 1.38
Common dividend declared		(45,715,000)							$ (45,715,000)
Stock Issued During Period, Value, Acquisitions		0
Proceeds from exercise of stock options, net of cash paid				5,873
Stock Repurchased During Period, Value, as a result of Stock Options Exercised		114,000						114,000
Stock based compensation		3,297,000						3,297,000
Restricted stock awards issued, net of awards surrendered				49,249
Restricted stock awards issued, net of awards surrendered		(1,186,000)			1,000			(1,187,000)
Shares issued under direct stock purchase plan				23,037
Shares issued under direct stock purchase plan		1,620,000						1,620,000
Stock Repurchased During Period, Shares				(1,500,000)
Stock Repurchased During Period, Value		(95,091,000)			(15,000)			(95,076,000)
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits						23,000	(23,000)
Increase (Decrease) in Deferred Compensation		0
Period End Balance at Sep. 30, 2020		1,689,724,000			328,000	(4,712,000)	4,712,000	944,218,000	696,546,000		48,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Off-Balance Sheet, Credit Loss, Liability, Change in Method, Credit Loss Expense (Reversal)		(1,000,000)
Off-Balance Sheet, Credit Loss, Liability, Change in Method, Credit Loss Expense (Reversal), net of tax.		736,000
Common Stock, Shares, Outstanding				32,942,110
Net income		34,873,000							$ 34,873,000
Other comprehensive income		(3,213,000)									(3,213,000)
Cash dividends declared per common share (in dollars per share)									$ 0.46
Common dividend declared		(15,161,000)							$ (15,161,000)
Proceeds from exercise of stock options, net of cash paid				5,000
Proceeds from exercise of stock options, net of cash paid					0
Stock Repurchased During Period, Value, as a result of Stock Options Exercised		140,000						140,000
Stock based compensation		868,000						868,000
Restricted stock awards issued, net of awards surrendered				(43)
Restricted stock awards issued, net of awards surrendered		(3,000)			0			(3,000)
Shares issued under direct stock purchase plan				8,480
Shares issued under direct stock purchase plan		528,000						528,000
Increase (Decrease) in Deferred Compensation and Other Retirement Benefits						(63,000)	63,000
Increase (Decrease) in Deferred Compensation		0
Period End Balance at Sep. 30, 2020		1,689,724,000			$ 328,000	$ (4,712,000)	$ 4,712,000	$ 944,218,000	$ 696,546,000		$ 48,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method, net of tax.		$ 817,000
Common Stock, Shares, Outstanding		32,955,547		32,955,547
Cumulative Effect of New Accounting Principle in Period of Adoption (Deprecated 2020-01-31)	[1]		$ 1,553,000							$ 1,553,000
[1]	Represents adjustment needed to reflect the cumulative impact on retained earnings pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment presented includes $1.1 million ($817,000, net of tax) attributable to the change in accounting methodology for estimating the allowance for credit losses and $1.0 million ($736,000, net of tax) related to the reserve for unfunded commitments resulting from the Company's adoption of the standard. Amount shown in the table above is presented net of tax.

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Common Stock, Shares, Outstanding	32,955,547		32,955,547			34,377,388
Stockholders' Equity Attributable to Parent	$ 1,689,724	$ 1,682,324	$ 1,689,724	$ 1,682,324	$ 1,671,692	$ 1,708,143	$ 1,636,003	$ 1,073,490
Held In Rabbi Trust At Cost [Member]
Stockholders' Equity Attributable to Parent	$ (4,712)	$ (4,713)	$ (4,712)	$ (4,713)	(4,649)	(4,735)	(4,648)	(4,718)
Retained Earnings
Cash dividends declared per common share (in dollars per share)	$ 0.46	$ 0.44	$ 1.38	$ 1.32
Stockholders' Equity Attributable to Parent	$ 696,546	$ 621,831	$ 696,546	$ 621,831	676,834	654,182	585,111	546,736
Deferred Compensation, Share-based Payments [Member]
Stockholders' Equity Attributable to Parent	4,712	4,713	4,712	4,713	4,649	4,735	4,648	4,718
AOCI Attributable to Parent [Member]
Stockholders' Equity Attributable to Parent	48,632	26,202	48,632	26,202	51,845	18,169	20,956	(1,173)
Common Stock [Member]
Stockholders' Equity Attributable to Parent	328	342	328	342	328	342	342	279
Additional Paid-in Capital [Member]
Stockholders' Equity Attributable to Parent	$ 944,218	$ 1,033,949	$ 944,218	$ 1,033,949	$ 942,685	$ 1,035,450	$ 1,029,594	$ 527,648
Common Class A [Member]
Common Stock, Shares, Outstanding	32,955,547	34,366,781	32,955,547	34,366,781	32,942,110	34,377,388	34,321,061	28,080,408

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 86,526,000	$ 117,698,000
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	21,071,000	13,919,000
Change In Unamortized Net Loan Costs And Premiums	(9,406,000)	(7,262,000)
Provision for credit losses	52,500,000	2,000,000
Deferred income tax expense	2,802,000	171,000
Net unrealized (gain) loss on equity securities	107,000	(1,562,000)
Gain (Loss) on Investments		1,462,000
Net loss on bank premises and equipment	363,000	180,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, After Tax	684,000	0
Gains (Losses) on Sales of Other Real Estate	0	389,000
Realized gain on sale leaseback transaction	(433,000)	(433,000)
Stock based compensation	3,297,000	3,413,000
Increase in cash surrender value of life insurance policies	(3,902,000)	(3,572,000)
Gain Realized on Life Insurance Policies	(692,000)	(434,000)
Operating Lease, Payments	(8,899,000)	(7,798,000)
Change in Fair Value on Loans Held for Sale	(1,252,000)	(1,192,000)
Net change in:
Trading assets	(433,000)	(459,000)
Loans held for sale	(20,154,000)	37,672,000
Other assets	(200,520,000)	(57,624,000)
Increase (Decrease) in Other Operating Liabilities	89,164,000	40,668,000
Total adjustments	(75,703,000)	19,538,000
Net cash provided by operating activities	10,823,000	137,236,000
Cash flows used in investing activities
Proceeds from Sale of Debt and Equity Securities, FV-NI, Held-for-investment	0	1,461,000
Increase (Decrease) in Equity Securities, FV-NI	(331,000)	(356,000)
Proceeds from Sale of Debt Securities, Available-for-sale		45,863,000
Proceeds from maturities and principal repayments of securities available for sale	74,898,000	35,770,000
Payments to Acquire Debt Securities, Available-for-sale	(58,704,000)	(16,230,000)
Proceeds from maturities and principal repayments of securities held to maturity	176,841,000	87,313,000
Purchases of securities held to maturity	(95,017,000)	(56,937,000)
Net redemption (purchases) of Federal Home Loan Bank stock	(666,000)	18,344,000
Investments in low income housing projects	(15,586,000)	(3,549,000)
Purchases of life insurance policies	(116,000)	(115,000)
Proceeds from Life Insurance Policy	2,629,000	3,162,000
Net increase in loans	(525,626,000)	(11,668,000)
Payments to Acquire Businesses, Net of Cash Acquired	0	(105,264,000)
Purchases of bank premises and equipment	(8,283,000)	(11,753,000)
Proceeds from the sale of bank premises and equipment	283,000	17,000
Payments on early termination of hedging relationship	(684,000)	0
Net cash used in investing activities	(450,362,000)	(13,942,000)
Cash flows provided by (used in) financing activities
Net increase (decrease) in time deposits	(336,289,000)	28,113,000
Net increase (decrease) in other deposits	2,040,615,000	(56,714,000)
Increase (Decrease) in Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Net	55,000,000	(177,046,000)
Increase Decrease in Federal Home Loan Bank Advances Long Term	(25,000,000)	(25,000,000)
Proceeds from Lines of Credit	0	49,980,000
Repayments of Lines of Credit	0	(49,980,000)
Repayments of Debt	(37,500,000)
Proceeds from (repayments of) long-term debt, net of issuance costs		74,867,000
RepaymentsOfJuniorSubordinatedDebt	0	(13,329,000)
Proceeds from Issuance of Subordinated Long-term Debt	0	49,526,000
Net Purchases from Stock Options Exercised	114,000
Net proceeds from exercise of stock options		(281,000)
Restricted stock awards issued, net of awards surrendered	(1,186,000)	(1,435,000)
Proceeds from shares issued under direct stock purchase plan	1,620,000	4,412,000
Payments for shares repurchased under share repurchase program	(95,091,000)	0
Common dividends paid	(45,681,000)	(38,152,000)
Net cash provided by (used in) financing activities	1,556,602,000	(154,477,000)
Net increase (decrease) in cash and cash equivalents	1,117,063,000	(31,183,000)
Cash and cash equivalents at beginning of year	150,974,000	250,455,000
Cash and cash equivalents at end of period	1,268,037,000	219,272,000
Supplemental schedule of noncash activities
Net increase in capital commitments relating to low income housing project investments	28,027,000	15,740,000
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	7,693,000	7,593,000
Stock Issued During Period, Value, Acquisitions	0	499,693,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	0	2,711,067,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	$ 0	$ 2,106,110,000

Investments is Low Income Housi

Investments is Low Income Housing Tax Credits Investments in Low Income Housing Tax Credits	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Investments in Low Income Housing Projects [Text Block]	LOW INCOME HOUSING PROJECT INVESTMENTS The Company has invested in low income housing projects that generate Low Income Housing Tax Credits (“LIHTC”) which provide the Company with tax credits and operating loss tax benefits over a period of approximately 15 years. None of the original investment is expected to be repaid. The following table presents certain information related to the Company's investments in low income housing projects as of the dates indicated: September 30 December 31 (Dollars in thousands) Original investment value $ 124,302 $ 96,275 Current recorded investment 94,097 72,510 Unfunded liability obligation 47,408 34,967 Tax credits and benefits 10,671 (1) 7,342 Amortization of investments 8,676 (2) 5,645 Net income tax benefit 1,995 (3) 1,696 (1) This amount reflects anticipated tax credits and tax benefits for the full year ended December 31, 2020. (2) The amortization amount reduces the tax credits and benefits anticipated for the full year ended December 31, 2020. (3) This amount represents the net tax benefit expected to be realized for the full year ended December 31, 2020 in determining the Company's effective tax rate.

Investments is Low Income Hou_2

Investments is Low Income Housing Tax Credits Investments in Low Income Housing Tax Credits - Tables	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Investments in Low Income Housing Projects [Table Text Block]	The following table presents certain information related to the Company's investments in low income housing projects as of the dates indicated: September 30 December 31 (Dollars in thousands) Original investment value $ 124,302 $ 96,275 Current recorded investment 94,097 72,510 Unfunded liability obligation 47,408 34,967 Tax credits and benefits 10,671 (1) 7,342 Amortization of investments 8,676 (2) 5,645 Net income tax benefit 1,995 (3) 1,696 (1) This amount reflects anticipated tax credits and tax benefits for the full year ended December 31, 2020. (2) The amortization amount reduces the tax credits and benefits anticipated for the full year ended December 31, 2020. (3) This amount represents the net tax benefit expected to be realized for the full year ended December 31, 2020 in determining the Company's effective tax rate.

Investments is Low Income Hou_3

Investments is Low Income Housing Tax Credits Investments in Qualified Affordable Housing Projects - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2020		Dec. 31, 2019
Investments in Affordable Housing Projects [Abstract]
Original investment value	$ 124,302		$ 96,275
Amortization Method Qualified Affordable Housing Project Investments	94,097		72,510
Capital commitment relating to low income housing project investments	47,408		34,967
Tax credits and benefits	10,671	[1]	7,342
Amortization of investments	8,676	[2]	5,645
Net income tax benefit	$ 1,995	[3]	$ 1,696
[1]	(1) This amount reflects anticipated tax credits and tax benefits for the full year ended December 31, 2020.
[2]	(2) The amortization amount reduces the tax credits and benefits anticipated for the full year ended December 31, 2020.
[3]	(3) This amount represents the net tax benefit expected to be realized for the full year ended December 31, 2020 in determining the Company's effective tax rate.

Recent Accounting Standards

Recent Accounting Standards	9 Months Ended
	Sep. 30, 2020
Recent Accounting Standards [Abstract]
RECENT ACCOUNTING STANDARDS	RECENT ACCOUNTING STANDARDS UPDATES Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 326 "Financial Instruments - Credit Losses" Update No. 2016-13. The standard was issued in June 2016 and has been amended three times by the FASB (collectively, the "updates"). The purpose of the updates is 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, these updates replace the incurred loss impairment methodology in current GAAP with a methodology, referred to as the current expected credit losses ("CECL") methodology, which reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The updates affect loans, debt securities, trade receivables, net investments in leases, off-balance sheet credit exposures, reinsurance receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. The Company adopted the CECL standard effective January 1, 2020. The Company adopted the standard using the modified retrospective method for all financial assets measured at amortized cost, net investment in leases and off-balance sheet credit exposures. Results for reporting periods beginning after January 1, 2020 are presented under the CECL standard, while prior period results are presented under standards previously applicable under GAAP. The cumulative effect of the Company's adoption resulted in an immaterial increase to retained earnings as of the January 1, 2020 adoption date. This transition adjustment was a result of the change in allowance methodology, including the impact to the reserve on unfunded commitments resulting from the application of new guidance under CECL, as well as the day one gross-up of purchased credit deteriorated ("PCD") assets. The standard was adopted using the prospective transition approach for PCD assets that were previously classified as purchased credit impaired ("PCI") assets. As prescribed by the standard, management did not reassess whether PCI assets met the criteria of PCD assets at the date of adoption. On January 1, 2020, the amortized cost basis of the PCD assets were adjusted to reflect estimated credit losses, with the remaining non-credit related discount, calculated based on the adjusted amortized cost, and will be accreted into interest income on a straight line basis over the remaining contractual term of the asset. See Note 3 - "Securities" and Note 4 - "Loans, Allowance for Credit Losses and Credit Quality" for further details surrounding the Company's adoption of CECL, related accounting policy updates and full disclosures required under the standard. FASB ASC Topic 848 "Reference Rate Reform" Update No. 2020-04. Update No. 2020-04 was issued in March 2020 to provide optional expedients and exceptions for applying GAAP to certain contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this update apply only to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate ("LIBOR") or another reference rate expected to be discontinued because of reference rate reform. The amendments will not apply to contract modifications made and hedging relationship entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022 for which an entity has elected certain optional expedients that are retained through the end of the hedging relationship. The amendments in this update are effective for all entities as of March 12, 2020 through December 31, 2022 and do not apply to contract modifications made after December 31, 2022. The Company has not yet adopted the

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION Independent Bank Corp. (the “Company”) is a state chartered, federally registered bank holding company, incorporated in 1985. The Company is the sole stockholder of Rockland Trust Company (“Rockland Trust” or the “Bank”), a Massachusetts trust company chartered in 1907. All material intercompany balances and transactions have been eliminated in consolidation. Certain previously reported amounts have been reclassified to conform to the current year’s presentation. The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation of the financial statements, primarily consisting of normal recurring adjustments, have been included. Results for the three and nine months ended September 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020 or any other interim period.

Securities

Securities	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Marketable Securities [Table Text Block]	SECURITIES Investment securities are classified at the time of purchase as available for sale, held to maturity, trading, or equity. Classification is constantly re-evaluated for consistency with corporate goals and objectives. Trading and equity securities are recorded at fair value with subsequent changes in fair value recorded in earnings. Debt securities that management has the positive intent and ability to hold to maturity are classified as held to maturity and recorded at amortized cost. Securities not classified as held to maturity or trading are classified as available for sale and recorded at fair value, with changes in fair value excluded from earnings and reported in other comprehensive income, net of related tax. Purchase premiums and discounts are recognized in interest income, using the interest method, to arrive at periodic interest income at a constant effective yield, thereby reflecting the securities market yield. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Accrued interest receivable balances are excluded from the amortized cost of held to maturity securities and the fair value of available for sale securities and are included within other assets on the consolidated balance sheet. Management has elected not to measure an allowance for credit losses on these balances as the Company employs a timely write-off policy. It is the Company's policy that a security is placed on nonaccrual status at the time any principal or interest payments become 90 days delinquent, and interest earned but not collected for a security placed on non-accrual is reversed against interest income. Allowance for Credit Losses - Available for Sale Securities The Company's available for sale securities are carried at fair value. For available for sale securities in an unrealized loss position, management will first evaluate whether there is intent to sell, or if it is more likely than not that the Company will be required to sell a security prior to anticipated recovery of its amortized cost basis. If either of these criteria are met, the Company will record a write-down of the security's amortized cost basis to fair value through income. For those available for sale securities which do not meet the intent or requirement to sell criteria, management will evaluate whether the decline in fair value is a result of credit related matters or other factors. In performing this assessment, management considers the creditworthiness of the issuer including whether the security is guaranteed by the U.S. Federal Government or other government agency, the extent to which fair value is less than amortized cost, and changes in credit rating during the period, among other factors. If this assessment indicates the existence of credit losses, the security will be written down to fair value, as determined by a discounted cash flow analysis. To the extent the estimated cash flows do not support the amortized cost, the deficiency is considered to be due to credit loss and is recognized in earnings. Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense. Losses are charged against the allowance when the uncollectibility of a security is confirmed, or when either of the aforementioned criteria surrounding intent or requirement to sell have been met. Allowance for Credit Losses - Held to Maturity Securities The Company measures expected credit losses on held to maturity securities on a collective basis by major security type. Management classifies the held to maturity portfolio into the following major security types: U.S. Government Agency, U.S. Treasury, Agency Mortgage-Backed Securities, Agency Collateralized Mortgage Obligations, Small Business Administration Pooled Securities, and Single Issuer Trust Preferred Securities. Securities in the Company's held to maturity portfolio are primarily guaranteed by either the U.S. Federal Government or other government sponsored agencies with a long history of no credit losses. As a result, management has determined these securities to have a zero loss expectation and therefore does not estimate an allowance for credit losses on these securities. Trading Securities The Company had trading securities of $2.6 million and $2.2 million as of September 30, 2020 and December 31, 2019, respectively. These securities are held in a rabbi trust and will be used for future payments associated with the Company’s nonqualified 401(k) Restoration Plan and Nonqualified Deferred Compensation Plan. Equity Securities The Company had equity securities of $21.1 million and $21.3 million as of September 30, 2020 and December 31, 2019, respectively. These securities consist primarily of mutual funds held in a rabbi trust and will be used for future payments associated with the Company’s supplemental executive retirement plans. The following table represents a summary of the gains and losses that relate to equity securities for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 Dollars in thousands Net gains (losses) recognized during the period on equity securities $ 308 $ 211 (107) 1,562 Less: net gains recognized during the period on equity securities sold during the period — — 6 6 Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting date $ 308 $ 211 $ (113) $ 1,556 Available for Sale Securities The following table summarizes the amortized cost, allowance for credit losses, and fair value of available for sale securities and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) as of the dates indicated: September 30, 2020 December 31, 2019 Amortized Gross Gross Unrealized Allowance for credit losses Fair Amortized Gross Gross Unrealized Fair (Dollars in thousands) U.S. government agency securities $ 22,475 $ 1,798 $ — $ — $ 24,273 $ 32,473 $ 642 $ — $ 33,115 Agency mortgage-backed securities 220,150 10,471 (1) — 230,620 243,548 3,456 (4) 247,000 Agency collateralized mortgage obligations 98,657 3,539 (119) — 102,077 87,305 1,225 (19) 88,511 State, county, and municipal securities 1,125 20 — — 1,145 1,377 19 — 1,396 Single issuer trust preferred securities issued by banks 489 — (20) — 469 488 5 — 493 Pooled trust preferred securities issued by banks and insurers 1,433 — (412) — 1,021 1,488 — (374) 1,114 Small business administration pooled securities 59,830 4,043 — — 63,873 54,024 771 — 54,795 Total available for sale securities $ 404,159 $ 19,871 $ (552) $ — $ 423,478 $ 420,703 $ 6,118 $ (397) $ 426,424 The Company did not record an allowance for estimated credit losses on any available for sale securities during the three and nine months ended September 30, 2020. Excluded from the table above is accrued interest on available for sale securities of $1.4 million as of September 30, 2020, which is included within other assets on the consolidated balance sheet. Additionally, the Company did not record any write-offs of accrued interest income on available for sale securities during the three and nine months ended September 30, 2020. No securities held by the Company were delinquent on contractual payments as of September 30, 2020, nor were any securities placed on non-accrual status during the three or nine months then ended. When securities are sold, the adjusted cost of the specific security sold is used to compute the gain or loss on the sale. The Company had no sales of securities available for sale during the three or nine months ended September 30, 2020, and therefore no gains or losses were realized during the periods presented. The Company had no sales of securities available for sale during the three months ended September 30, 2019 and recorded realized losses of $1.5 million on sales of securities available for sale during the nine months ended September 30, 2019. The following table shows the gross unrealized losses and fair value of the Company’s available for sale securities which are in an unrealized loss position, and for which the Company has not recorded an allowance for credit losses as of September 30, 2020. These available for sale securities are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position: September 30, 2020 Less than 12 months 12 months or longer Total # of Fair Unrealized Fair Unrealized Fair Unrealized (Dollars in thousands) Agency mortgage-backed securities 2 399 (1) — — 399 (1) Agency collateralized mortgage obligations 2 27,269 (119) — — 27,269 (119) Single issuer trust preferred securities issued by banks and insurers 1 469 (20) — — 469 (20) Pooled trust preferred securities issued by banks and insurers 1 — — 1,021 (412) 1,021 (412) Total impaired available for sale securities 6 $ 28,137 $ (140) $ 1,021 $ (412) $ 29,158 $ (552) The Company does not intend to sell these investments and has determined, based upon available evidence, that it is more likely than not that the Company will not be required to sell each security before the recovery of its amortized cost basis. As a result, the Company did not recognize an allowance for credit losses on these investments during the three or nine months ended September 30, 2020. The Company made this determination by reviewing various qualitative and quantitative factors regarding each investment category, such as current market conditions, extent and nature of changes in fair value, issuer rating changes and trends, volatility of earnings, and current analysts’ evaluations. As a result of the Company’s review of these qualitative and quantitative factors, the causes of the impairments listed in the table above by category were as follows at September 30, 2020: • Agency Mortgage-Backed Securities and Agency Collateralized Mortgage Obligations: These portfolios have contractual terms that generally do not permit the issuer to settle the securities at a price less than the current par value of the investment. The decline in market value of these securities is attributable to changes in interest rates and not credit quality. Additionally, these securities are implicitly guaranteed by the U.S. Government or one of its agencies. • Single Issuer Trust Preferred Securities: This portfolio consists of one security, which is investment grade. The unrealized loss on this security is attributable to the illiquid nature of the trust preferred market in the current economic environment. Management evaluates various financial metrics for the issuer, including regulatory capital ratios of the issuer. • Pooled Trust Preferred Securities: This portfolio consists of one below investment grade security which is performing. The unrealized loss on this security is attributable to the illiquid nature of the trust preferred market in the current economic and regulatory environment. Management evaluates collateral credit and instrument structure, including current and expected deferral and default rates and timing. In addition, discount rates are determined by evaluating comparable spreads observed currently in the market for similar instruments. Held to Maturity Securities The following table summarizes the amortized cost, fair value and allowance for credit losses of held to maturity securities and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) as of the dates indicated: September 30, 2020 December 31, 2019 Amortized Gross Gross Unrealized Allowance for credit losses Fair Amortized Gross Gross Unrealized Fair (Dollars in thousands) U.S. government agency securities $ — $ — $ — $ — $ — $ 12,874 $ 123 $ — $ 12,997 U.S. Treasury securities 4,021 79 — — 4,100 4,032 21 — 4,053 Agency mortgage-backed securities 388,106 19,687 — — 407,793 397,414 8,445 (57) 405,802 Agency collateralized mortgage obligations 237,380 9,557 — — 246,937 293,662 4,501 (849) 297,314 Single issuer trust preferred securities issued by banks 1,500 — (2) — 1,498 1,500 — (10) 1,490 Small business administration pooled securities 28,566 1,573 — — 30,139 31,324 338 (55) 31,607 Total held to maturity securities $ 659,573 $ 30,896 $ (2) $ — $ 690,467 $ 740,806 $ 13,428 $ (971) $ 753,263 The Company did not record an allowance for estimated credit losses on any held to maturity securities during the three and nine months ended September 30, 2020. Excluded from the table above is accrued interest on held to maturity securities of $1.7 million as of September 30, 2020, which is included within other assets on the consolidated balance sheet. Additionally, the Company did not record any write-offs of accrued interest income on held to maturity securities during the three and nine months ended September 30, 2020. No securities held by the Company were delinquent on contractual payments as of September 30, 2020, nor were any securities placed on non-accrual status during the three and nine months then ended. When securities are sold, the adjusted cost of the specific security sold is used to compute the gain or loss on the sale. The Company had no sales of held to maturity securities during the three and nine months ended September 30, 2020 and 2019, and therefore no gains or losses were realized during the periods presented. The Company monitors the credit quality of held to maturity securities through the use of credit ratings. Credit ratings are monitored by the Company on at least a quarterly basis. As of September 30, 2020, all held to maturity securities held by the Company were rated investment grade or higher. The actual maturities of certain available for sale or held to maturity securities may differ from the contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. A schedule of the contractual maturities of available for sale and held to maturity securities as of September 30, 2020 is presented below: Due in one year or less Due after one year to five years Due after five to ten years Due after ten years Total Amortized Fair Amortized Fair Amortized Fair Amortized Fair Amortized Fair (Dollars in thousands) Available for sale securities U.S. government agency securities $ — $ — $ 10,001 $ 10,288 $ 12,474 $ 13,985 $ — $ — $ 22,475 $ 24,273 Agency mortgage-backed securities — — 71,624 73,773 38,956 41,956 109,570 114,891 220,150 230,620 Agency collateralized mortgage obligations — — — — — — 98,657 102,077 98,657 102,077 State, county, and municipal securities 515 516 420 422 190 207 — — 1,125 1,145 Single issuer trust preferred securities issued by banks — — — — — — 489 469 489 469 Pooled trust preferred securities issued by banks and insurers — — — — — — 1,433 1,021 1,433 1,021 Small business administration pooled securities — — — — — — 59,830 63,873 59,830 63,873 Total available for sale securities $ 515 $ 516 $ 82,045 $ 84,483 $ 51,620 $ 56,148 $ 269,979 $ 282,331 $ 404,159 $ 423,478 Held to maturity securities U.S. Treasury securities $ 1,001 $ 1,019 $ 3,020 $ 3,081 $ — $ — $ — $ — $ 4,021 $ 4,100 Agency mortgage-backed securities 8,510 8,574 1,458 1,509 53,530 56,289 324,608 341,421 388,106 407,793 Agency collateralized mortgage obligations — — — — — — 237,380 246,937 237,380 246,937 Single issuer trust preferred securities issued by banks — — — — 1,500 1,498 — — 1,500 1,498 Small business administration pooled securities — — — — — — 28,566 30,139 28,566 30,139 Total held to maturity securities $ 9,511 $ 9,593 $ 4,478 $ 4,590 $ 55,030 $ 57,787 $ 590,554 $ 618,497 $ 659,573 $ 690,467 Total $ 10,026 $ 10,109 $ 86,523 $ 89,073 $ 106,650 $ 113,935 $ 860,533 $ 900,828 $ 1,063,732 $ 1,113,945 Included in the table above are $3.9 million of callable securities at September 30, 2020. The carrying value of securities pledged to secure public funds, trust deposits, and for other purposes, as required or permitted by law, was $417.1 million and $375.5 million at September 30, 2020 and December 31, 2019, respectively. At September 30, 2020 and December 31, 2019, the Company had no investments in obligations of individual states, counties, or municipalities which exceeded 10% of consolidated stockholders’ equity. Under previous accounting guidance, the Company reviewed both available for sale and held to maturity securities for other-than-temporary-impairment ("OTTI"). However, in accordance with the newly adopted CECL standard, the Company now utilizes separate impairment models for held to maturity and available for sale securities for purposes of estimating credit losses. The following table shows the gross unrealized losses and fair value of the Company’s investments in an unrealized loss position, which the Company had not deemed to be OTTI, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2019: December 31, 2019 Less than 12 months 12 months or longer Total # of Fair Unrealized Fair Unrealized Fair Unrealized (Dollars in thousands) Agency mortgage-backed securities 12 34,009 (59) 243 (2) 34,252 (61) Agency collateralized mortgage obligations 17 48,476 (215) 37,382 (653) 85,858 (868) Single issuer trust preferred securities issued by banks and insurers 1 — — 1,490 (10) 1,490 (10) Pooled trust preferred securities issued by banks and insurers 1 — — 1,114 (374) 1,114 (374) Small business administration pooled securities 1 7,349 (55) — — 7,349 (55) Total temporarily impaired securities 32 $ 89,834 $ (329) $ 40,229 $ (1,039) $ 130,063 $ (1,368)

Loans, Allowance for Credit Los

Loans, Allowance for Credit Losses and Credit Quality (Notes)	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Loans, Allowance for Credit Losses and Credit Quality [Text Block]	LOANS, ALLOWANCE FOR CREDIT LOSSES AND CREDIT QUALITY Loans Held for Sale The Bank primarily classifies new residential real estate mortgage loans as held for sale based on intent, which is determined when loans are underwritten. Residential real estate mortgage loans not designated as held for sale are retained based upon available liquidity, for interest rate risk management and other business purposes. The Company has elected the fair value option to account for originated closed loans intended for sale. Accordingly, changes in fair value relating to loans intended for sale are recorded in earnings and are offset by changes in fair value relating to interest rate lock commitments and forward sales commitments. Gains and losses on residential loan sales (sales proceeds minus carrying amount) are recorded in mortgage banking income. Upfront costs and fees related to items for which the fair value option is elected are recognized in earnings as incurred and are not deferred. Loans Loans that the Company has the intent and ability to hold until maturity or payoff are carried at amortized cost (net of the allowance for credit losses). Amortized cost is the principal amount outstanding, adjusted by partial charge-offs and net of deferred loan costs or fees. For originated loans, loan fees and certain direct origination costs are deferred and amortized into interest income over the expected term of the loan using the level-yield method. When a loan is paid off, the unamortized portion is recognized in interest income. Interest income on loans is accrued based upon the daily principal amount outstanding except for loans on nonaccrual status. As a general rule, loans 90 days or more past due with respect to principal or interest are classified as nonaccrual loans, or sooner if management considers such action to be prudent. However, loans that are 90 days or more past due may be kept on an accruing status if the loan is well secured and in the process of collection. The Company may also put a junior lien mortgage on nonaccrual status as a result of delinquency with respect to the first position, which is held by the Bank or by another financial institution, while the junior lien is currently performing. Income accruals are suspended on all nonaccrual loans in a timely manner and all previously accrued and uncollected interest is reversed against current income. A loan remains on nonaccrual status until it becomes current with respect to principal and interest (and in certain instances remains current for up to six months), the loan is liquidated, or when the loan is determined to be uncollectible and is charged-off against the allowance for credit losses. When doubt exists as to the collectability of a loan, any payments received are applied to reduce the amortized cost of the loan to the extent necessary to eliminate such doubt. For all loan portfolios, a charge-off occurs when the Company determines that a specific loan, or portion thereof, is uncollectible. This determination is made based on management's review of specific facts and circumstances of the individual loan, including assessing the viability of the customer’s business or project as a going concern, the expected cash flows to repay the loan, the value of the collateral and the ability and willingness of any guarantors to perform. Allowance for Credit Losses - Loans Held for Investment The allowance for credit losses is established based upon the Company's current estimate of expected lifetime credit losses on loans measured at amortized cost. Loan losses are charged against the allowance when management's assessments confirm that the Company will not collect the full amortized cost basis of a loan. Subsequent recoveries, if any, are credited to the allowance. Under the CECL methodology, the Company estimates credit losses for financial assets on a collective basis for loans sharing similar risk characteristics using a quantitative model combined with an assessment of certain qualitative factors designed to address forecast risk and model risk inherent in the quantitative model output. The quantitative model utilizes a factor based approach to estimate expected credit losses using Probability of Default ("PD"), Loss Given Default ("LGD") and Exposure at Default ("EAD"), which are derived from internal historical default and loss experience. The model estimates expected credit losses using loan level data over the estimated life of the exposure, considering the effect of prepayments. Economic forecasts are incorporated into the estimate over a reasonable and supportable forecast period, beyond which is a reversion to the Company's historical long-run average. Management has determined a reasonable and supportable period of 12 months, and a straight line reversion period of 6 months, to be appropriate for purposes of estimating expected credit losses. The qualitative risk factors impacting the expected risk of loss within the portfolio include the following: • Lending policies and procedures • Economic and business conditions • Nature and volume of loans • Changes in management • Changes in credit quality • Changes in loan review system • Changes to underlying collateral values • Concentrations of credit risk • Other external factors Loans that do not share similar risk characteristics with any pools of assets are subject to individual assessment and are removed from the collectively assessed pools to avoid double counting. For the loans that are individually assessed, the Company uses either a discounted cash flow (“DCF”) approach or a fair value of collateral approach. The latter approach is used for loans deemed to be collateral dependent or when foreclosure is probable. Accrued interest receivable amounts are excluded from balances of loans held at amortized cost and are included within other assets on the consolidated balance sheet. Management has elected not to measure an allowance for credit losses on these amounts as the Company employs a timely write-off policy. Consistent with the Company's policy for nonaccrual loans, accrued interest receivable is typically written off when loans reach 90 days past due and are placed on nonaccrual status. In the ordinary course of business, the Company enters into commitments to extend credit, commercial letters of credit, and standby letters of credit. Such financial instruments are recorded in the financial statements when they become payable. The credit risk associated with these commitments is evaluated in a manner similar to the allowance for credit losses. The reserve for unfunded lending commitments is included in other liabilities on the consolidated balance sheet. Acquired Loans Prior to its adoption of CECL, and under legacy GAAP, the Company maintained a portfolio of acquired loans, which, at acquisition, were recorded at fair value with no carryover of the allowance for loan losses. Acquired loans were also reviewed to determine if the loan had evidence of deterioration in credit quality and also if it was probable, at acquisition, that all contractually required payments would not be collected. Loans meeting such criteria were deemed to be purchased credit impaired ("PCI") loans. Under the accounting model for PCI loans, the excess of cash flows expected to be collected over the carrying amount of the loans, referred to as the "accretable yield", was accreted into interest income over the life of the loans using the effective yield method. Accordingly, PCI loans were not subject to classification as nonaccrual in the same manner as originated loans. Rather, acquired PCI loans were generally considered to be accruing loans because their interest income related to the accretable yield recognized and not to contractual interest payments at the loan level. The difference between contractually required principal and interest payments and the cash flows expected to be collected, referred to as the "nonaccretable difference", included estimates of both the impact of prepayments and future credit losses expected to be incurred over the life of the loans. Under the CECL standard, the concept of PCI assets was effectively replaced with purchased credit deteriorated ("PCD") assets, the balances of which should be treated in a manner consistent with loans held for investment for purposes of estimating an allowance for credit losses. As a result, upon the Company's adoption of CECL on January 1, 2020, loan balances previously classified as PCI assets were re-classified as PCD assets and have been prospectively accounted for in accordance with the standard. See Note 2 - Recent Accounting Standards Updates for further discussion surrounding the day one impact associated with adoption of CECL as it relates to PCI assets. Loans Held for Investment and Allowance for Credit Losses The following table summarizes the change in allowance for credit losses by loan category, and bifurcates the amount of loans allocated to each loan category for the period indicated: Three Months Ended September 30, 2020 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for credit losses Beginning balance $ 25,662 $ 36,956 $ 4,501 $ 4,561 $ 15,046 $ 24,860 $ 590 $ 112,176 Charge-offs (185) (3,885) — (49) — — (185) (4,304) Recoveries 1 9 — 2 1 21 219 253 Provision for credit loss expense 2,741 6,306 709 79 (884) (1,309) (142) 7,500 Ending balance (1) $ 28,219 $ 39,386 $ 5,210 $ 4,593 $ 14,163 $ 23,572 $ 482 $ 115,625 Nine Months Ended September 30, 2020 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for credit losses Beginning balance, pre adoption of Topic 326 $ 17,594 $ 32,935 $ 6,053 $ 1,746 $ 3,440 $ 5,576 $ 396 $ 67,740 Cumulative effect accounting adjustment (2) (1,984) (13,048) (3,652) 495 9,828 7,012 212 (1,137) Cumulative effect accounting adjustment (3) 49 337 — — 423 319 29 1,157 Charge-offs (185) (3,885) — (194) — (142) (1,342) (5,748) Recoveries 47 9 — 8 2 174 873 1,113 Provision for credit loss expense 12,698 23,038 2,809 2,538 470 10,633 314 52,500 Ending balance (1) $ 28,219 $ 39,386 $ 5,210 $ 4,593 $ 14,163 $ 23,572 $ 482 $ 115,625 (1) Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $36.7 million as of September 30, 2020. (2) Represents adjustment needed to reflect the cumulative day one impact pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.1 million decrease to the allowance attributable to the change in accounting methodology for estimating the allowance for credit losses resulting from the Company's adoption of the standard. (3) Represents adjustment needed to reflect the day one reclassification of the Company's PCI loan balances to PCD and the associated gross-up, pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.2 million increase to the allowance resulting from the day one reclassification. The balance of allowance for credit losses of $115.6 million as of September 30, 2020 represents an increase of $47.9 million, or 70.6%, in comparison to the implementation balances at January 1, 2020, and an increase of $3.4 million, or 3.1% compared to June 30, 2020. These increases in the allowance were primarily driven by anticipated credit deterioration caused by the COVID-19 pandemic. During the third quarter, conditions surrounding the credit environment and expectations for future loss estimates did not change significantly in comparison to the previous quarter. As a result, the third quarter provision for credit losses of $7.5 million reflects a decrease from the $25.0 million and $20.0 million recorded during the first and second quarters, respectively. While management is unable to know with certainty the direct, indirect, and future impacts of the COVID-19 pandemic, it is expected that the pandemic will have a material adverse impact on future losses across a broad range of loan segments. As such, the provision for credit loss recognized in 2020 reflects increased reserve allocations to loan segments that are considered to have elevated loss exposure associated with the COVID-19 pandemic. These loan segments primarily include commercial relationships within industries that are subject to mandated closures and capacity limits that will potentially impede the borrowers’ ability to make loan payments, including loans in the following industry sections: Accommodations, Food Services, Retail Trade, Recreation and Entertainment, and Other Services (excluding Public Administration). In addition to these industry exposures, additional risk of loss was attributable to non-owner occupied real estate borrowers with significant retail tenant exposure, as well as home equity loans within a junior lien position. Leveraging actual historical loss given default (LGD) rates combined with stressing of assumptions over probability of default rates over these higher risk segments, qualitative adjustments were made to the initially model-driven calculated loss reserves. Additionally, the forecast used by the model was adjusted to use a more severe outlook at each quarter end throughout 2020, as compared to the baseline forecast that was used to calculate opening balances on January 1, 2020 as a result of the uncertainty in the outlook due to the ongoing pandemic. For the purpose of estimating the allowance for credit losses, management segregated the loan portfolio into the portfolio segments detailed in the above tables. Each of these loan categories possesses unique risk characteristics that are considered when determining the appropriate level of allowance for each segment. Some of the characteristics unique to each loan category include: Commercial Portfolio • Commercial and Industrial : Loans in this category consist of revolving and term loan obligations extended to business and corporate enterprises for the purpose of financing working capital and/or capital investment. Collateral generally consists of pledges of business assets including, but not limited to: accounts receivable, inventory, plant and equipment, or real estate, if applicable. Repayment sources consist of primarily, operating cash flow, and secondarily, liquidation of assets. • Commercial Real Estate : Loans in this category consist of mortgage loans to finance investment in real property such as multi-family residential, commercial/retail, office, industrial, hotels, educational and healthcare facilities and other specific use properties. Loans are typically written with amortizing payment structures. Collateral values are determined based upon third party appraisals and evaluations. Loan to value ratios at origination are governed by established policy and regulatory guidelines. Repayment sources consist of, primarily, cash flow from operating leases and rents and, secondarily, liquidation of assets. • Commercial Construction : Loans in this category consist of short-term construction loans, revolving and nonrevolving credit lines and construction/permanent loans to finance the acquisition, development and construction or rehabilitation of real property. Project types include residential land development, 1-4 family, condominium, and multi-family home construction, commercial/retail, office, industrial, hotels, educational and healthcare facilities and other specific use properties. Loans may be written with nonamortizing or hybrid payment structures depending upon the type of project. Collateral values are determined based upon third party appraisals and evaluations. Loan to value ratios at origination are governed by established policy and regulatory guidelines. Repayment sources vary depending upon the type of project and may consist of sale or lease of units, operating cash flows or liquidation of other assets. • Small Business: Loans in this category consist of revolving, term loan and mortgage obligations extended to sole proprietors and small businesses for purposes of financing working capital and/or capital investment. Collateral generally consists of pledges of business assets including, but not limited to, accounts receivable, inventory, plant and equipment, or real estate if applicable. Repayment sources consist primarily of operating cash flows and, secondarily, liquidation of assets. For the commercial portfolio it is the Company’s policy to obtain personal guarantees for payment from individuals holding material ownership interests in the borrowing entities. Consumer Portfolio • Residential Real Estate : Residential mortgage loans held in the Company’s portfolio are made to borrowers who demonstrate the ability to make scheduled payments with full consideration to underwriting factors such as current and expected income, employment status, current assets, other financial resources, credit history and the value of the collateral. Collateral consists of mortgage liens on 1-4 family residential properties. Residential mortgage loans also include loans to construct owner-occupied 1-4 family residential properties. • Home Equity : Home equity loans and credit lines are made to qualified individuals and are primarily secured by senior or junior mortgage liens on owner-occupied 1-4 family homes, condominiums or vacation homes. Each home equity loan has a fixed rate and is billed in equal payments comprised of principal and interest. The majority of home equity lines of credit have a variable rate and are billed in interest-only payments during the draw period. At the end of the draw period, the home equity line of credit is billed as a percentage of the then outstanding principal balance plus all accrued interest over a predetermined repayment period, as set forth in the note. Additionally, the Company has the option of renewing each line of credit for additional draw periods. Borrower qualifications include favorable credit history combined with supportive income requirements and combined loan to value ratios within established policy guidelines. • Other Consumer: Other consumer loan products include personal lines of credit and amortizing loans made to qualified individuals for various purposes such as education, debt consolidation, personal expenses or overdraft protection. Borrower qualifications include favorable credit history combined with supportive income and collateral requirements within established policy guidelines. These loans may be secured or unsecured. Credit Quality The Company continually monitors the asset quality of the loan portfolio using all available information. Based on this information, loans demonstrating certain payment issues or other weaknesses may be categorized as adversely risk-rated, delinquent, nonperforming and/or put on nonaccrual status. Additionally, in the course of resolving such loans, the Company may choose to restructure the contractual terms of certain loans to match the borrower’s ability to repay the loan based on their current financial condition. The Company reviews numerous credit quality indicators when assessing the risk in its loan portfolio. For the commercial portfolio, the Company utilizes a 10-point credit risk-rating system, which assigns a risk-grade to each loan obligation based on a number of quantitative and qualitative factors associated with a commercial or small business loan transaction. Factors considered include industry and market conditions, position within the industry, earnings trends, operating cash flow, asset/liability values, debt capacity, guarantor strength, management and controls, financial reporting, collateral, and other considerations. The risk-rating categories for the commercial portfolio are defined as follows: • Pass: Risk-rating “1” through “6” comprises of loans ranging from ‘Substantially Risk Free’ which indicates borrowers are of unquestioned credit standing and the pinnacle of credit quality, well established companies with a very strong financial condition, and loans fully secured by cash collateral, through ‘Acceptable Risk’, which indicates borrowers may exhibit declining earnings, strained cash flow, increasing or above average leverage and/or weakening market fundamentals that indicate below average asset quality, margins and market share. Collateral coverage is protective. • Potential Weakness: Borrowers exhibit potential credit weaknesses or downward trends deserving management’s close attention. If not checked or corrected, these trends will weaken the Company’s asset and position. While potentially weak, currently these borrowers are marginally acceptable; no loss of principal or interest is envisioned. • Definite Weakness Loss Unlikely: Borrowers exhibit well defined weaknesses that jeopardize the orderly liquidation of debt. Loans may be inadequately protected by the current net worth and paying capacity of the obligor or by the collateral pledged, if any. Normal repayment from the borrower is in jeopardy, although no loss of principal is envisioned. However, there is a distinct possibility that a partial loss of interest and/or principal will occur if the deficiencies are not corrected. Collateral coverage may be inadequate to cover the principal obligation. • Partial Loss Probable: Borrowers exhibit well defined weaknesses that jeopardize the orderly liquidation of debt with the added provision that the weaknesses make collection of the debt in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. Serious problems exist to the point where partial loss of principal is likely. • Definite Loss: Borrowers deemed incapable of repayment. Loans to such borrowers are considered uncollectible and of such little value that continuation as active assets of the Company is not warranted. The Company utilizes a comprehensive, continuous strategy for evaluating and monitoring commercial credit quality. Initially, credit quality is determined at loan origination and is re-evaluated when subsequent actions, such as renewals, modifications or reviews, occur. Actively managed commercial borrowers are required to provide updated financial information at least annually which is carefully evaluated for any changes in credit quality. Larger loan relationships are subject to a full annual credit review by experienced credit professionals, while continuous portfolio monitoring techniques are employed to evaluate changes in credit quality for smaller loan relationships. Any changes in credit quality are reflected in risk-rating changes. Additionally, the Company retains an independent loan review firm to evaluate the credit quality of the commercial loan portfolio. The independent loan review process achieves significant penetration into the commercial loan portfolio and reports the results of these reviews to the Audit Committee of the Board of Directors on a quarterly basis. Commercial loan modifications granted by the Company allowing payment deferrals for qualifying borrowers in accordance with the Coronavirus Aid, Relief and Economic Security Act ("CARES Act") have been assessed for downgrades of risk ratings. For the Company’s consumer portfolio, the quality of the loan is best indicated by the repayment performance of an individual borrower. As a result, for this portfolio the Company utilizes a pass/default risk-rating system, based on an age analysis (i.e., days past due) associated with each consumer loan. Under this structure, consumer loans less than 90 days past due are assigned a "pass" rating, while any consumer loans 90 days or more past due are assigned a "default" rating. Consumer loan modifications granted by the Company allowing payment deferrals for qualifying borrowers in accordance with the CARES Act have not been reflected as delinquent loans. The following table details the amortized cost balances of the Company's loan portfolios, presented by credit quality indicator and origination year as of the date indicated below: September 30, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving converted to Term Total (Dollars in thousands) Commercial and Pass $ 1,012,974 (1) $ 153,137 $ 107,318 $ 34,826 $ 23,065 $ 22,334 $ 601,937 $ 2,577 $ 1,958,168 Potential weakness 2,560 2,302 7,833 4,573 1,219 318 15,248 50 34,103 Definite weakness - loss unlikely 2,732 1,553 22,748 5,500 2,483 1,419 33,496 — 69,931 Partial loss probable — — — — — 143 — — 143 Definite loss — — — — — — — — — Total commercial and industrial $ 1,018,266 $ 156,992 $ 137,899 $ 44,899 $ 26,767 $ 24,214 $ 650,681 $ 2,627 $ 2,062,345 Commercial real estate Pass $ 753,415 $ 859,548 $ 512,371 $ 587,345 $ 399,442 $ 751,629 $ 39,998 $ 16,341 $ 3,920,089 Potential weakness 20,639 15,957 20,313 7,941 27,253 47,875 — — 139,978 Definite weakness - loss unlikely 4,261 2,265 10,092 21,081 2,170 6,605 — — 46,474 Partial loss probable — — 18,923 — — — — — 18,923 Definite loss — — — — — — — — — Total commercial real estate $ 778,315 $ 877,770 $ 561,699 $ 616,367 $ 428,865 $ 806,109 $ 39,998 $ 16,341 $ 4,125,464 Commercial construction Pass $ 182,291 $ 196,420 $ 73,298 $ 66,406 $ — $ 6,750 $ 31,372 $ 1,077 $ 557,614 Potential weakness — 9,352 5,037 — — — 328 — 14,717 Definite weakness - loss unlikely — — 1,003 — — — — — 1,003 Partial loss probable — — — — — — — — — Definite loss — — — — — — — — — Total commercial construction $ 182,291 $ 205,772 $ 79,338 $ 66,406 $ — $ 6,750 $ 31,700 $ 1,077 $ 573,334 Small business Pass $ 27,457 $ 28,766 $ 20,806 $ 14,627 $ 14,528 $ 22,644 $ 34,569 $ — $ 163,397 Potential weakness — 10 16 10 755 232 736 — 1,759 Definite weakness - loss unlikely 184 408 78 170 98 723 786 — 2,447 Partial loss probable — — — — — — 29 — 29 Definite loss — — — — — — — — — Total small business $ 27,641 $ 29,184 $ 20,900 $ 14,807 $ 15,381 $ 23,599 $ 36,120 $ — $ 167,632 Residential real estate Pass $ 131,691 $ 167,901 $ 187,194 $ 168,048 $ 241,638 $ 449,219 $ — $ — $ 1,345,691 Default 728 — 760 235 167 4,724 — — 6,614 Total residential real estate $ 132,419 $ 167,901 $ 187,954 $ 168,283 $ 241,805 $ 453,943 $ — $ — $ 1,352,305 Home equity Pass $ 60,274 $ 66,238 $ 59,534 $ 59,387 $ 44,817 $ 122,397 $ 681,784 $ 4,057 $ 1,098,488 Default — — — — — 455 2,044 67 2,566 Total home equity $ 60,274 $ 66,238 $ 59,534 $ 59,387 $ 44,817 $ 122,852 $ 683,828 $ 4,124 $ 1,101,054 Other consumer Pass $ 679 $ 450 $ 209 $ 739 $ 696 $ 7,737 $ 12,493 $ — $ 23,003 Default — — — 20 — 34 2 — 56 Total other consumer $ 679 $ 450 $ 209 $ 759 $ 696 $ 7,771 $ 12,495 $ — $ 23,059 Total $ 2,199,885 $ 1,504,307 $ 1,047,533 $ 970,908 $ 758,331 $ 1,445,238 $ 1,454,822 $ 24,169 $ 9,405,193 (1) Loans originated as part of the Paycheck Protection Program ("PPP") program established by the CARES Act are included within commercial and industrial under the 2020 vintage year and "pass" category as these loans are 100% guaranteed by the U.S. Government. Funded PPP loans totaled $811.7 million as of September 30, 2020. For the Company’s consumer portfolio, the quality of the loan is best indicated by the repayment performance of an individual borrower. However, the Company does supplement performance data with current Fair Isaac Corporation (“FICO”) scores and Loan to Value (“LTV”) estimates. Current FICO data is purchased and appended to all consumer loans on a regular basis. In addition, automated valuation services and broker opinions of value are used to supplement original value data for the residential and home equity portfolios, periodically. The following table shows the weighted average FICO scores and the weighted average combined LTV ratios at the dates indicated below: September 30 December 31 Residential portfolio FICO score (re-scored)(1) 749 749 LTV (re-valued)(2) 57.7 % 59.0 % Home equity portfolio FICO score (re-scored)(1) 770 767 LTV (re-valued)(2)(3) 46.6 % 46.6 % (1) The average FICO scores at September 30, 2020 are based upon rescores available from August 2020 and origination score data for loans booked in September 2020. The average FICO scores at December 31, 2019 were based upon rescores available from November 2019 and origination score data for loans booked in December 2019. (2) The combined LTV ratios for September 30, 2020 are based upon updated automated valuations as of August 2020, when available, and/or the most current valuation data available. The combined LTV ratios for December 31, 2019 were based upon updated automated valuations as of November 2019, when available, and/or the most current valuation data available as of such date. The updated automated valuations provide new information on loans that may be available since the previous valuation was obtained. If no new information is available, the valuation will default to the previously obtained data or most recent appraisal. (3) For home equity loans and lines in a subordinate lien, the LTV data represents a combined LTV, taking into account the senior lien data for loans and lines. Unfunded Commitments Management evaluates the need for a reserve on unfunded lending commitments in a manner consistent with loans held for investment. At September 30, 2020, the Company's estimated reserve for unfunded commitments amounted to $1.0 million. Asset Quality The Company’s philosophy toward managing its loan portfolios is predicated upon careful monitoring, which stresses early detection and response to delinquent and default situations. Delinquent loans are managed by a team of collection specialists and the Company seeks to make arrangements to resolve any delinquent or default situation over the shortest possible time frame. As a general rule, loans 90 days or more past due with respect to principal or interest are classified as nonaccrual loans. The Company also may use discretion regarding other loans 90 days or more delinquent if the loan is well secured and/or in process of collection. In response to the COVID-19 pandemic, the Company has granted loan modifications to allow deferral of payments for borrowers negatively impacted by the pandemic. The amount of loans with active deferrals as of September 30, 2020 was $583.8 million. The majority of these loans with active deferrals continue to be characterized as current loans. In accordance with regulatory guidance, these modifications are not considered to be troubled debt restructures ("TDRs") if they were performing prior to December 31, 2019. Additionally, a majority of these are characterized as current and therefore are not impacting nonaccrual or delinquency totals as of September 30, 2020. The Company does, however, consider all active deferrals when estimating loss reserves. As loans reach their deferral maturity date, consideration of TDR and delinquency status will resume in accordance with the Company's accounting policy. The following table shows information regarding nonaccrual loans as of the dates indicated: Nonaccrual Balances September 30, 2020 December 31, 2019 With Allowance for Credit Losses Without Allowance for Credit Losses Total Total (Dollars in thousands) Commercial and industrial $ 17,816 $ 19,035 $ 36,851 $ 22,574 Commercial real estate 17,501 20,663 38,164 3,016 Small business 542 — 542 311 Residential real estate 13,379 2,850 16,229 13,360 Home equity 6,052 107 6,159 6,570 Other consumer 79 — 79 61 Total nonaccrual loans (1) $ 55,369 $ 42,655 $ 98,024 $ 45,892 (1) Included in these amounts were $23.8 million and $24.8 million of nonaccruing TDRs at September 30, 2020 and December 31, 2019, respectively. It is the Company's policy to reverse any accrued interest when a loan is put on nonaccrual status, and, as such, the Company did not record any interest income on nonaccrual loans during the three and nine months ended September 30, 2020. The following table shows information regarding foreclosed residential real estate property at the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Foreclosed residential real estate property held by the creditor $ — $ — Recorded investment in mortgage loans collateralized by residential real estate property that are in the process of foreclosure $ 2,113 $ 3,294 The following tables show the age analysis of past due financing receivables as of the dates indicated: September 30, 2020 30-59 days 60-89 days 90 days or more Total Past Due Total Amortized Cost Number Principal Number Principal Number Principal Number Principal Current (Dollars in thousands) Loan Portfolio Commercial and industrial 1 $ 52 6 $ 3,608 5 $ 930 12 $ 4,590 $ 2,057,755 $ 2,062,345 $ — Commercial real estate 1 99 2 8,269 5 1,355 8 9,723 4,115,741 4,125,464 — Commercial construction — — —

Loans, Allowance for Loan Losse

Loans, Allowance for Loan Losses and Credit Quality	9 Months Ended
	Sep. 30, 2020
Loans, Allowance for Loan Losses and Credit Quality [Abstract]
LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY	LOANS AND ALLOWANCE FOR LOAN LOSSES As disclosed in Note 2 - " Recent Accounting Standards Updates " and Note 4 - " Loans, Allowance for Credit Losses and Credit Quality ," the Company adopted the CECL standard, effective January 1, 2020. As required by disclosure guidance, the Company has included relevant disclosures from the prior year and prior to the adoption of CECL within this footnote, as it relates to loans and allowance for loan losses. The following table bifurcates the amount of loans and the allowance allocated to each loan category based on the type of impairment analysis as of December 31, 2019: December 31, 2019 Commercial Commercial Commercial Small Residential Home Other Consumer Total (Dollars in thousands) Financing receivables ending balance: Collectively evaluated for impairment $ 1,370,580 $ 3,987,848 $ 547,293 $ 173,960 $ 1,571,848 $ 1,127,963 $ 29,663 $ 8,809,155 Individually evaluated for impairment 24,456 8,337 — 537 11,228 4,948 122 49,628 Purchased credit impaired loans — 6,174 — — 7,493 887 302 14,856 Total loans by group $ 1,395,036 $ 4,002,359 $ 547,293 $ 174,497 $ 1,590,569 $ 1,133,798 $ 30,087 $ 8,873,639 (1) (1) The amount of net deferred costs on originated loans included in the ending balance was $7.1 million at December 31, 2019. Net unamortized discounts on acquired loans not deemed to be purchased credit impaired ("PCI") included in the ending balance was $21.6 million at December 31, 2019. At December 31, 2019, the reserve for unfunded loan commitments was $2.1 million. The following table summarizes changes in allowance for loan losses by loan category for the periods indicated: Three Months Ended September 30, 2019 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for loan losses Beginning balance $ 16,857 $ 32,660 $ 5,593 $ 1,768 $ 3,296 $ 5,547 $ 239 $ 65,960 Charge-offs — (82) — (125) — (28) (472) (707) Recoveries 1,003 106 — 61 140 194 185 1,689 Provision (benefit) (528) (33) 240 48 (88) 36 325 — Ending balance $ 17,332 $ 32,651 $ 5,833 $ 1,752 $ 3,348 $ 5,749 $ 277 $ 66,942 Nine Months Ended September 30, 2019 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for loan losses Beginning balance $ 15,760 $ 32,370 $ 5,158 $ 1,756 $ 3,219 $ 5,608 $ 422 $ 64,293 Charge-offs — (82) — (319) — (212) (1,125) (1,738) Recoveries 1,127 152 — 108 141 278 581 2,387 Provision (benefit) 445 211 675 207 (12) 75 399 2,000 Ending balance $ 17,332 $ 32,651 $ 5,833 $ 1,752 $ 3,348 $ 5,749 $ 277 $ 66,942 Ending balance: collectively evaluated for impairment $ 17,326 $ 32,610 $ 5,833 $ 1,741 $ 2,729 $ 5,594 $ 272 $ 66,105 Ending balance: individually evaluated for impairment $ 6 $ 41 $ — $ 11 $ 619 $ 155 $ 5 $ 837 The Company's historical approach to loan portfolio segmentation by risk characteristics and monitoring of credit quality for commercial loans under previous accounting guidance was consistent with that applied under the newly adopted CECL standard. See Note 4 - "Loans, Allowance for Credit Losses and Credit Quality" further discussion surrounding the Company's policies for loan segmentation and credit quality monitoring. The following tables detail the amount of outstanding principal balances relative to each of the risk-rating categories for the Company’s loan portfolio as of December 31, 2019: December 31, 2019 Category Risk Commercial and Commercial Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 1,274,155 $ 3,860,555 $ 542,608 $ 171,213 $ 5,848,531 Potential weakness 7 63,485 97,268 2,247 1,416 164,416 Definite weakness-loss unlikely 8 57,396 44,536 2,438 1,868 106,238 Partial loss probable 9 — — — — — Definite loss 10 — — — — — Total $ 1,395,036 $ 4,002,359 $ 547,293 $ 174,497 $ 6,119,185 Impaired Loans Under previous accounting guidance, a loan was considered impaired when, based on current information and events, it was probable that the Company would be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment included payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experienced insignificant payment delays and payment shortfalls generally were not classified as impaired. Management determined the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. The table below sets forth information regarding the Company’s impaired loans by loan portfolio at the date indicated: December 31, 2019 Recorded Unpaid Related (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 23,786 $ 34,970 $ — Commercial real estate 6,213 12,101 — Small business 469 484 — Residential real estate 4,976 5,123 — Home equity 3,764 3,893 — Other consumer 34 34 — Subtotal 39,242 56,605 — With an allowance recorded Commercial and industrial $ 670 $ 670 $ 126 Commercial real estate 2,124 2,124 48 Small business 68 105 8 Residential real estate 6,252 7,163 637 Home equity 1,184 1,382 156 Other consumer 88 91 5 Subtotal 10,386 11,535 980 Total $ 49,628 $ 68,140 $ 980 The following table sets forth information regarding interest income recognized on impaired loans, by portfolio, for the periods indicated: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Average Interest Average Interest (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 25,694 $ 35 $ 27,937 $ 108 Commercial real estate 12,987 149 13,261 478 Small business 235 3 266 10 Residential real estate 5,031 57 5,061 175 Home equity 4,417 50 4,479 151 Other consumer 39 1 43 2 Subtotal 48,403 295 51,047 924 With an allowance recorded Commercial and industrial $ 353 $ 4 $ 360 $ 13 Commercial real estate 1,402 20 1,415 60 Small business 92 — 95 2 Residential real estate 6,047 61 6,115 179 Home equity 959 11 972 33 Other consumer 107 1 116 3 Subtotal 8,960 97 9,073 290 Total $ 57,363 $ 392 $ 60,120 $ 1,214 Purchased Credit Impaired Loans Under previous accounting guidance, certain loans acquired by the Company may have shown evidence of deterioration of credit quality since origination at purchase date, and it was therefore deemed unlikely that the Company would be able to collect all contractually required payments. As such, these loans were deemed to be PCI loans and the carrying value and prospective income recognition were predicated upon future cash flows expected to be collected. The following table displays certain information pertaining to PCI loans at the date indicated: December 31, 2019 (Dollars in thousands) Outstanding balance $ 18,358 Carrying amount $ 14,856 The following table summarizes activity in the accretable yield for the PCI loan portfolio for the periods indicated: Three Months Ended September 30 Nine Months Ended September 30 2019 2019 (Dollars in thousands) Beginning balance $ 2,238 $ 1,191 Acquisition — 1,464 Accretion (412) (1,215) Other change in expected cash flows (1) 237 623 Reclassification from nonaccretable difference for loans which have paid off 227 227 Ending balance $ 2,290 $ 2,290

Goodwill (Notes)

Goodwill (Notes)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	GOODWILL AND OTHER INTANGIBLE ASSETS The following table sets forth the carrying value of goodwill and other intangible assets, net of accumulated amortization, at the dates indicated below: September 30, 2020 December 31, 2019 (Dollars in thousands) Balances not subject to amortization Goodwill $ 506,206 $ 506,206 Balances subject to amortization Core deposit intangibles 23,625 28,016 Other intangible assets 918 1,270 Total other intangible assets 24,543 29,286 Total goodwill and other intangible assets $ 530,749 $ 535,492

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Earnings per share consisted of the following components for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands, except per share data) Net income $ 34,873 $ 51,845 $ 86,526 $ 117,698 Weighted Average Shares Basic shares 32,951,918 34,361,176 33,358,879 32,283,196 Effect of dilutive securities 24,758 39,390 27,871 45,416 Diluted shares 32,976,676 34,400,566 33,386,750 32,328,612 Net income per share Basic EPS $ 1.06 $ 1.51 $ 2.59 $ 3.65 Effect of dilutive securities — — — (0.01) Diluted EPS $ 1.06 $ 1.51 $ 2.59 $ 3.64 The diluted earnings per share computations do not assume the conversion, exercise, or contingent issuance of the following shares for the following periods because the result would have been anti-dilutive for the periods indicated. As a result of the anti-dilution, the potential common shares excluded from the calculation of diluted earnings per share are as follows: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 Stock options 10,000 5,000 10,000 — Performance-based restricted stock — — 11,080 —

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
STOCK BASED COMPENSATION	STOCK BASED COMPENSATION Time Vested Restricted Stock Awards During the nine months ended September 30, 2020, the Company made the following awards of time vested restricted stock: Date Shares Granted Plan Grant Date Fair Value Per Share Vesting Period 2/27/2020 46,550 2005 Employee Stock Plan $ 70.24 Ratably over 5 years from grant date 4/15/2020 880 2005 Employee Stock Plan $ 68.14 Ratably over 5 years from grant date 5/27/2020 9,438 2018 Non-Employee Director Stock Plan $ 72.86 Shares vested immediately The fair value of the restricted stock awards is based upon the average of the high and low price at which the Company’s common stock traded on the date of grant. The holders of restricted stock awards are entitled to receive dividends and to vote from and as of the date of grant. Performance-Based Restricted Stock Awards On February 27, 2020, the Company granted 17,100 performance-based restricted stock awards to certain executive level employees. These performance-based restricted stock awards were issued from the 2005 Employee Stock Plan and were determined to have a grant date fair value per share of $70.24, determined by the average of the high and low price at which the Company's common stock traded on the date of grant. The number of shares to be vested is contingent upon the Company's attainment of certain performance measures outlined in the award agreement and will be measured as of the end of the three year performance period, January 1, 2020 through December 31, 2022. The awards will vest upon the earlier of the date on which it is determined if the performance goal is achieved subsequent to the performance period or March 31, 2023. These awards are accounted for as equity awards due to the nature of these awards and the fact that these shares will not be settled in cash. The holders of these awards are not entitled to receive dividends or vote until the shares are vested. On March 3, 2020, the performance-based restricted stock awards that were awarded on February 16, 2017 vested at 100% of the maximum target shares awarded, or 14,400 shares. Stock Options The Company did not grant any awards of options to purchase shares of common stock during the nine months ended September 30, 2020.

Income Taxes (Notes)

Income Taxes (Notes)	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	INCOME TAXES The following table sets forth information regarding the Company’s tax provision and applicable tax rates for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands) Combined federal and state income tax provision $ 11,199 $ 17,036 $ 21,126 $ 38,565 Effective income tax rate 24.31 % 24.73 % 19.62 % 24.68 %

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value is a market-based measure considered from the perspective of a market participant rather than an entity-specific measure. Therefore, even when market assumptions are not readily available, the assumptions applied by the Company when determining fair value reflect those that the Company determines market participants would use to price the asset or liability at the measurement date. If there has been a significant decrease in the volume and level of activity for the asset or liability, regardless of the valuation technique(s) used, the objective of a fair value measurement remains the same. Fair value is the price that would be received if the asset were to be sold or that would be or paid if the liability were to be transferred in an orderly market transaction (that is, not a forced liquidation or distressed sale) between market participants at the measurement date under current market conditions. When determining fair value, the Company considers pricing information and other inputs that are current as of the measurement date. In periods of market dislocation, the observability of prices and other inputs may be reduced for certain instruments, or not available at all. The unavailability or reduced availability of pricing or other input information could cause an instrument to be reclassified from one level to another. The Fair Value Measurements and Disclosures Topic of the FASB ASC defines fair value and establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under the Fair Value Measurements and Disclosures Topic of the FASB ASC are described below: Level 1 – Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 – Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation Techniques There have been no changes in the valuation techniques used during the three and nine months ended September 30, 2020. Securities Trading and Equity Securities These equity securities are valued based on market quoted prices. These securities are categorized in Level 1 as they are actively traded and no valuation adjustments have been applied. U.S. Government Agency Securities Fair value is estimated using either multi-dimensional spread tables or benchmarks. The inputs used include benchmark yields, reported trades, and broker/dealer quotes. These securities are classified as Level 2. Agency Mortgage-Backed Securities Fair value is estimated using either a matrix or benchmarks. The inputs used include benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. These securities are categorized as Level 2. Agency Collateralized Mortgage Obligations and Small Business Administration Pooled Securities The valuation model for these securities is volatility-driven and ratings based, and uses multi-dimensional spread tables. The inputs used include benchmark yields, reported trades, new issue data, broker dealer quotes, and collateral performance. If there is at least one significant model assumption or input that is not observable, these securities are categorized as Level 3 within the fair value hierarchy; otherwise, they are classified as Level 2. State, County, and Municipal Securities The fair value is estimated using a valuation matrix with inputs including bond interest rate tables, recent transactions, and yield relationships. These securities are categorized as Level 2. Single and Pooled Issuer Trust Preferred Securities The fair value of trust preferred securities, including pooled and single issuer preferred securities, is estimated using external pricing models, discounted cash flow methodologies or similar techniques. The inputs used in these valuations include benchmark yields, reported trades, new issue data, broker dealer quotes, and collateral performance. If there is at least one significant model assumption or input that is not observable, these securities are classified as Level 3 within the fair value hierarchy; otherwise, they are classified as Level 2. Loans Held for Sale The Company has elected the fair value option to account for originated closed loans intended for sale. The fair value is measured on an individual loan basis using quoted market prices and when not available, comparable market value or discounted cash flow analysis may be utilized. These assets are typically classified as Level 2. Derivative Instruments Derivatives 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. The Company incorporates credit valuation adjustments to appropriately reflect 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. Additionally, in conjunction with fair value measurement guidance, the Company has made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Although the Company has determined that the majority of the inputs used to value its interest rate derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its interest rate derivatives and risk participation agreements may also utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. However, as of September 30, 2020 and December 31, 2019, the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are properly classified as Level 2. Mortgage Derivatives The fair value of mortgage derivatives is determined based on current market prices for similar assets in the secondary market and, therefore, classified as Level 2 within the fair value hierarchy. Individually Assessed Collateral Dependent Loans In accordance with the CECL standard, expected credit losses on individually assessed loans deemed to be collateral dependent are valued based upon the lower of amortized cost or fair value of the underlying collateral less costs to sell. The inputs used in the appraisals of the collateral are not always observable, and in such cases the loans may be classified as Level 3 within the fair value hierarchy; otherwise, they are classified as Level 2. Other Real Estate Owned and Other Foreclosed Assets Other Real Estate Owned ("OREO") and Other Foreclosed Assets are valued at the lower of cost or fair value of the property, less estimated costs to sell. The fair values are generally estimated based upon recent appraisal values of the property less costs to sell the property. Certain inputs used in appraisals are not always observable, and therefore OREO and Other Foreclosed Assets may be classified as Level 3 within the fair value hierarchy. Goodwill and Other Intangible Assets Goodwill and other intangible assets are subject to impairment testing. The Company conducts an annual impairment test of goodwill in the third quarter of each year, or more frequently if necessary. Other intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. To estimate the fair value of goodwill and, if necessary, other intangible assets, the Company utilizes both a comparable analysis of relevant price multiples in recent market transactions and a discounted cash flow analysis. Both valuation models require a significant degree of management judgment. In the event the fair value as determined by the valuation model is less than the carrying value, the intangibles may be impaired. If the impairment testing resulted in impairment, the Company would classify the impaired goodwill and other intangible assets subjected to nonrecurring fair value adjustments as Level 3. Assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows as of the dates indicated: Fair Value Measurements at Reporting Date Using Balance Quoted Prices Significant Significant September 30, 2020 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 2,612 $ 2,612 $ — $ — Equity securities 21,119 21,119 — — Securities available for sale U.S. government agency securities 24,273 — 24,273 — Agency mortgage-backed securities 230,620 — 230,620 — Agency collateralized mortgage obligations 102,077 — 102,077 — State, county, and municipal securities 1,145 — 1,145 — Single issuer trust preferred securities issued by banks and insurers 469 — 469 — Pooled trust preferred securities issued by banks and insurers 1,021 — — 1,021 Small business administration pooled securities 63,873 — 63,873 — Loans held for sale 54,713 — 54,713 — Derivative instruments 210,742 — 210,742 — Liabilities Derivative instruments 151,613 — 151,613 — Total recurring fair value measurements $ 561,051 $ 23,731 $ 536,299 $ 1,021 Nonrecurring fair value measurements Assets Individually assessed collateral dependent loans $ 56,660 $ — $ — $ 56,660 Total nonrecurring fair value measurements $ 56,660 $ — $ — $ 56,660 Fair Value Measurements at Reporting Date Using Balance Quoted Prices Significant Significant December 31, 2019 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 2,179 $ 2,179 $ — $ — Equity securities 21,261 21,261 — — Securities available for sale U.S. government agency securities 33,115 — 33,115 — Agency mortgage-backed securities 247,000 — 247,000 — Agency collateralized mortgage obligations 88,511 — 88,511 — State, county, and municipal securities 1,396 — 1,396 — Single issuer trust preferred securities issued by banks and insurers 493 — 493 — Pooled trust preferred securities issued by banks and insurers 1,114 — — 1,114 Small business administration pooled securities 54,795 — 54,795 — Loans held for sale 33,307 — 33,307 — Derivative instruments 78,385 — 78,385 — Liabilities Derivative instruments 53,923 — 53,923 — Total recurring fair value measurements $ 507,633 $ 23,440 $ 483,079 $ 1,114 Nonrecurring fair value measurements: Assets Collateral dependent impaired loans $ 25,515 $ — $ — $ 25,515 Total nonrecurring fair value measurements $ 25,515 $ — $ — $ 25,515 The table below presents a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3), which were valued using pricing models and discounted cash flow methodologies, for the periods indicated: Three Months Ended September 30 2020 2019 (Dollars in thousands) Pooled Trust Preferred Securities Beginning balance $ 986 $ 1,281 Gain and (losses) (realized/unrealized) Included in other comprehensive income 41 (14) Settlements (6) (161) Ending balance $ 1,021 $ 1,106 Nine Months Ended September 30 2020 2019 (Dollars in thousands) Pooled Trust Preferred Securities Beginning balance $ 1,114 $ 1,329 Losses (realized/unrealized) Included in other comprehensive income (38) (38) Settlements (55) (185) Ending balance $ 1,021 $ 1,106 The following table sets forth certain unobservable inputs regarding the Company’s financial instruments that are classified as Level 3 as of the dates indicated: September 30 December 31 September 30 December 31 September 30 December 31 Valuation Technique Fair Value Unobservable Inputs Range Weighted Average (Dollars in thousands) Discounted cash flow methodology Pooled trust preferred securities $ 1,021 $ 1,114 Cumulative prepayment 0% - 56% 0% - 57% 2.6% 2.6% Cumulative default 4% - 100% 2% - 100% 11.9% 13.5% Loss given default 85% - 100% 85% - 100% 94.0% 93.6% Cure given default 0% - 75% 0% - 75% 60.9% 60.9% Appraisals of collateral(1) Individually assessed collateral dependent loans $ 56,660 n/a Collateral dependent impaired loans n/a $ 25,515 (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary. The significant unobservable inputs used in the fair value measurement of the Company’s pooled trust preferred securities are cumulative prepayment rates, cumulative default rates, loss given default rates and cure given default rates. Significant increases (decreases) in deferrals or defaults, in isolation, would result in a significantly lower (higher) fair value measurement. Alternatively, significant increases (decreases) in cure rates, in isolation, would result in a significantly higher (lower) fair value measurement. The estimated fair values and related carrying amounts for assets and liabilities for which fair value is only disclosed are shown below as of the dates indicated: Fair Value Measurements at Reporting Date Using Carrying Fair Quoted Prices Significant Significant September 30, 2020 (Dollars in thousands) Financial assets Securities held to maturity(a) U.S. Treasury securities $ 4,021 $ 4,100 $ — $ 4,100 $ — Agency mortgage-backed securities 388,106 407,793 — 407,793 — Agency collateralized mortgage obligations 237,380 246,937 — 246,937 — Single issuer trust preferred securities issued by banks 1,500 1,498 — 1,498 — Small business administration pooled securities 28,566 30,139 — 30,139 — Loans, net of allowance for credit losses(b) 9,232,908 9,185,023 — — 9,185,023 Federal Home Loan Bank stock(c) 15,090 15,090 — 15,090 — Cash surrender value of life insurance policies(d) 199,453 199,453 — 199,453 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 9,792,667 $ 9,792,667 $ — $ 9,792,667 $ — Time certificates of deposits(f) 1,058,641 1,065,818 — 1,065,818 — Federal Home Loan Bank borrowings(f) 145,765 145,975 — 145,975 — Long-term borrowings(f) 37,447 36,448 — 36,448 — Junior subordinated debentures(g) 62,850 67,883 — 67,883 — Subordinated debentures(f) 49,672 47,173 — — 47,173 Fair Value Measurements at Reporting Date Using Carrying Fair Quoted Prices Significant Significant December 31, 2019 (Dollars in thousands) Financial assets Securities held to maturity(a) U.S. government agency securities $ 12,874 $ 12,997 $ — $ 12,997 $ — U.S. Treasury securities 4,032 4,053 $ — 4,053 — Agency mortgage-backed securities 397,414 405,802 — 405,802 — Agency collateralized mortgage obligations 293,662 297,314 — 297,314 — Single issuer trust preferred securities issued by banks 1,500 1,490 — 1,490 — Small business administration pooled securities 31,324 31,607 — 31,607 — Loans, net of allowance for credit losses(b) 8,780,384 8,613,635 — — 8,613,635 Federal Home Loan Bank stock(c) 14,424 14,424 — 14,424 — Cash surrender value of life insurance policies(d) 197,372 197,372 — 197,372 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 7,752,052 $ 7,752,052 $ — $ 7,752,052 $ — Time certificates of deposits(f) 1,395,315 1,396,760 — 1,396,760 — Federal Home Loan Bank borrowings(f) 115,748 115,881 — 115,881 — Long-term borrowings (f) 74,906 72,219 — 72,219 — Junior subordinated debentures(g) 62,848 65,603 — 65,603 — Subordinated debentures(f) 49,601 52,870 — — 52,870 (a) The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis. (b) Fair value of loans is measured using the exit price valuation method, determined primarily by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows, while incorporating liquidity and credit assumptions. Additionally, this amount excludes individually assessed collateral dependent loans, which are deemed to be marked to fair value on a nonrecurring basis. (c) Federal Home Loan Bank stock has no quoted market value and is carried at cost; therefore the carrying amount approximates fair value. (d) Cash surrender value of life insurance policies is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore, carrying amount approximates fair value. (e) Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date. (f) Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities. (g) Fair value was determined based upon market prices of securities with similar terms and maturities. This summary excludes certain financial assets and liabilities for which the carrying value approximates fair value. For financial assets, these may include cash and due from banks, federal funds sold and short-term investments. For financial liabilities, these may include federal funds purchased. These instruments would all be considered to be classified as Level 1 within the fair value hierarchy. Also excluded from the summary are financial instruments measured at fair value on a recurring and nonrecurring basis, as previously described. The Company considers its current use of financial instruments to be the highest and best use of the instruments.

Revenue Recognition (Notes)

Revenue Recognition (Notes)	9 Months Ended
	Sep. 30, 2020
Revenue Recognition [Abstract]
Revenue from Contract with Customer [Text Block]	REVENUE RECOGNITION A portion of the Company's noninterest income is derived from contracts with customers, and as such, the revenue recognized depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company considers the terms of the contract and all relevant facts and circumstances when applying this guidance. To ensure its alignment with this core principle, the Company measures revenue and the timing of recognition by applying the following five steps: 1. Identify the contract(s) with customers 2. Identify the performance obligations 3. Determine the transaction price 4. Allocate the transaction price to the performance obligations 5. Recognize revenue when (or as) the entity satisfies a performance obligation The Company has disaggregated its revenue from contracts with customers into categories that depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. The following table presents the revenue streams that the Company has disaggregated as of the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 September 30 September 30 (Dollars in thousands) Deposit account fees (inclusive of cash management fees) $ 3,428 $ 5,299 $ 11,227 $ 14,785 Interchange fees 2,025 4,913 10,665 13,473 ATM fees 708 939 1,872 2,461 Investment management - wealth management and advisory services 6,997 6,635 20,113 19,127 Investment management - retail investments and insurance revenue 574 553 1,583 1,962 Merchant processing income 330 230 1,000 834 Credit card income 216 — 550 — Other noninterest income 905 1,487 2,651 4,068 Total noninterest income in-scope of ASC 606 15,183 20,056 49,661 56,710 Total noninterest income out-of-scope of ASC 606 14,164 11,760 34,311 25,287 Total noninterest income $ 29,347 $ 31,816 $ 83,972 $ 81,997 In each of the revenue streams identified above, there were no significant judgments made in determining or allocating the transaction price, as the consideration and service requirements are generally explicitly identified in the associated contracts. Additional information related to each of the revenue streams is further noted below. Deposit Account Fees The Company offers various deposit account products to its customers governed by specific deposit agreements applicable to either personal customers or business customers. These agreements identify the general conditions and obligations of both parties, and include standard information regarding deposit account related fees. Deposit account services include providing access to deposit accounts as well as access to the various deposit transactional services of the Company. These transactional services are primarily those that are identified in the standard fee schedule, and include, but are not limited to, services such as overdraft protection, wire transfer, and check collection. Revenue is recognized in conjunction with the various services being provided. For example, the Company may assess monthly fixed service fees associated with the customer having access to a deposit account, which can vary depending on the account type and daily account balance. In addition, the Company may also assess separate fixed fees associated with and at the time specific transactions are entered into by the customer. As such, the Company considers its performance obligations to be met concurrently with providing the account access or completing the requested deposit transaction. Cash Management Cash management services are a subset of the deposit account fees revenue stream. These services primarily include ACH transaction processing, positive pay and remote deposit services. These services are also governed by separate agreements entered into with the customer. The fee arrangement for these services is structured to assess fees under one of two scenarios, either a per transaction fee arrangement or an earnings credit analysis arrangement. Under the per transaction fee arrangement, fixed fees are assessed concurrently with customers executing the transactions, and as such, the Company considers its performance obligations to be met concurrently with completing the requested transaction. Under the earnings credit analysis arrangement, the Company provides a monthly earnings credit to the customer that is negotiated and determined based on various factors. The credit is then available to absorb the per transaction fees that are assessed on the customer's deposit account activity for the month. Any amount of the transactional fees in excess of the earnings credit is recognized as revenue in that month. Interchange Fees The Company earns interchange revenue from its issuance of credit and debit cards granted through its membership in various card payment networks. The Company provides credit cards and debit cards to its customers which are authorized and settled through these payment networks, and in exchange, the Company earns revenue as determined by each payment network's interchange program. The revenue is recognized concurrently with the settlement of card transactions within each network. ATM Fees The Company deploys automated teller machines (ATMs) as part of its overall branch network. Certain transactions performed at the ATMs require customers to acknowledge and pay a fee for the requested service. Certain ATM fees are disclosed in the deposit account agreement fee schedules, whereas those assessed to non-Rockland Trust deposit holders are solely determined during the transaction at the machine. The ATM fee is a fixed dollar per transaction amount, and as such, is recognized concurrently with the overall daily processing and settlement of the ATM activity. Investment Management - Wealth Management and Advisory Services The Company offers investment management and trust services to individuals, institutions, small businesses and charitable institutions. Each investment management product is governed by its own contract along with a separate identifiable fee schedule unique to that product. The Company also offers additional services, such as estate settlement, financial planning, tax services and other special services quoted at the client's request. The asset management and/or custody fees are based upon a percentage of the monthly valuation of the principal assets in the customer's account, whereas fees for additional or special services are fixed in nature and are charged as services are rendered. As the fees are dependent on assets under management, which are susceptible to market factors outside of the Company's control, this variable consideration is constrained and therefore no revenue is estimated at contract initiation. As such, all revenue is recognized in correlation to the monthly management fee determinations or as transactional services are provided. Due to the fact that payments are primarily made subsequent to the valuation period, the Company records a receivable for revenue earned but not received. The following table provides the amount of investment management revenue earned but not received as of the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Receivables, included in other assets $ 4,383 $ 2,341 Investment Management - Retail Investments and Insurance Revenue The Company offers the sale of mutual fund shares, unit investment trust shares, general securities, fixed and variable annuities and life insurance products through registered representatives who are both employed by the Company and licensed and contracted with various broker general agents to offer these products to the Company’s customer base. As such, the Company performs these services as an agent and earns a fixed commission on the sales of these products and services. To a lesser degree, production bonus commissions can also be earned based upon the Company meeting certain volume thresholds. In general, the Company recognizes commission revenue at the point of sale, and for certain insurance products, may also earn and recognize annual residual commissions commensurate with annual premiums being paid. Merchant Processing Income The Company refers customers to third party merchant processing partners in exchange for commission and fee income. The income earned is comprised of multiple components, including a fixed referral fee per each referred customer, a rebate amount determined primarily as a percentage of net revenue earned by the third party from services provided to each referred customer, and overall production bonus commissions if certain new account production thresholds are met. Merchant processing income is recognized in conjunction with either completing the referral to earn the fixed fee amount or as the merchant activity is processed to derive the Company's rebate and/or production bonus amounts. Credit Card Income The Company provides consumer and business credit card solutions to its customers by soliciting new accounts on behalf of a third party credit card provider in exchange for a fee. The income earned is comprised of new account incentive payments as well as a percentage of interchange income earned by the third party provider offering the consumer and business purpose revolving credit accounts. The credit card income is recognized in conjunction with the establishment of each new credit card member or as the interchange is earned by the third party in connection with net purchase transactions made by the credit card member. Other Noninterest Income The Company earns various types of other noninterest income that fall within the scope of the new revenue recognition rules, and have been aggregated into one general revenue stream in the table noted above. This amount includes, but is not limited to, the following types of revenue with customers: Safe Deposit Rent The Company rents out the use of safe deposit boxes to its customers, which can be accessed when the bank is open for business. The safe deposit box rental fee is paid upfront and is recognized as revenue ratably over the annual term of the contract. 1031 Exchange Fee Revenue The Company provides like-kind exchange services pursuant to Section 1031 of the Internal Revenue Code. Fee income is recognized in conjunction with completing the exchange transactions. Foreign Currency

Comprehensive Income_Loss

Comprehensive Income/Loss	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
COMPREHENSIVE INCOME/LOSS	OTHER COMPREHENSIVE INCOME (LOSS) The following tables present a reconciliation of the changes in the components of other comprehensive income (loss) for the periods indicated, including the amount of income tax (expense) benefit allocated to each component of other comprehensive income (loss): Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (857) $ 148 $ (709) $ 13,598 $ (3,265) $ 10,333 Less: net security losses reclassified into other noninterest expense — — — — — — Net change in fair value of securities available for sale (857) 148 (709) 13,598 (3,265) 10,333 Change in fair value of cash flow hedges (143) 41 (102) 37,674 (10,597) 27,077 Less: net cash flow hedge gains reclassified into interest income or interest expense 4,339 (1,220) 3,119 9,901 (2,784) 7,117 Less: Loss on termination of hedge reclassified into noninterest expense (684) 192 (492) (684) 192 (492) Net change in fair value of cash flow hedges (3,798) 1,069 (2,729) 28,457 (8,005) 20,452 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (2) 1 (1) (1,392) 392 (1,000) Amortization of net actuarial losses 245 (69) 176 736 (207) 529 Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 312 (87) 225 (449) 127 (322) Total other comprehensive income (loss) $ (4,343) $ 1,130 $ (3,213) $ 41,606 $ (11,143) $ 30,463 Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ 2,858 $ (683) $ 2,175 $ 14,699 $ (3,401) $ 11,298 Less: net security losses reclassified into other noninterest expense — — — (1,462) 411 (1,051) Net change in fair value of securities available for sale 2,858 (683) 2,175 16,161 (3,812) 12,349 Change in fair value of cash flow hedges 4,568 (1,285) 3,283 21,913 (6,167) 15,746 Less: net cash flow hedge gains reclassified into interest income or interest expense 352 (99) 253 1,170 (329) 841 Net change in fair value of cash flow hedges 4,216 (1,186) 3,030 20,743 (5,838) 14,905 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (11) 3 (8) (33) 9 (24) Amortization of net actuarial gains (2) 1 (1) (6) 2 (4) Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 56 (15) 41 168 (47) 121 Total other comprehensive income $ 7,130 $ (1,884) $ 5,246 $ 37,072 $ (9,697) $ 27,375 (1) The amortization of prior service costs is included in the computation of net periodic pension cost as disclosed in the Employee Benefit Plans footnote in the Company's Annual Report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission. Information on the Company’s accumulated other comprehensive income (loss), net of tax, is comprised of the following components as of the dates indicated: Unrealized Gain (Loss) Unrealized Gain on Cash Flow Hedge Defined Benefit Postretirement Plans Accumulated Other Comprehensive Income (Loss) (Dollars in thousands) 2020 Beginning balance: January 1, 2020 $ 4,398 $ 16,479 $ (2,708) $ 18,169 Net change in other comprehensive income (loss) 10,333 20,452 (322) 30,463 Ending balance: September 30, 2020 $ 14,731 $ 36,931 $ (3,030) $ 48,632 2019 Beginning balance: January 1, 2019 $ (5,947) $ 6,148 $ (1,374) $ (1,173) Net change in other comprehensive income (loss) 12,349 14,905 121 27,375 Ending balance: September 30, 2019 $ 6,402 $ 21,053 $ (1,253) $ 26,202

Commitments and contingencies

Commitments and contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	COMMITMENTS AND CONTINGENCIES Financial Instruments with Off-Balance Sheet Risk In the normal course of business, the Company enters into various transactions to meet the financing needs of its customers, which, in accordance with GAAP, are not included in its consolidated balance sheets. These transactions include commitments to extend credit and standby letters of credit, and loan exposures with recourse, which involve, to varying degrees, elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Company minimizes its exposure to loss under these commitments by subjecting them to credit approval and monitoring procedures. The Company enters into contractual commitments to extend credit, normally with fixed expiration dates or termination clauses, at specified rates and for specific purposes. Substantially all of these commitments to extend credit are contingent upon customers maintaining specific credit standards at the time of loan funding. The Company has certain loan exposures for which there is recourse. These loan relationships could require the Company to repurchase or cover certain losses per agreements for certain loans that are either sold or referred to third parties. Standby letters of credit are written conditional commitments issued to guarantee the performance of a customer to a third party. In the event the customer does not perform in accordance with the terms of the agreement with the third party, the Company would be required to fund the commitment. The maximum potential amount of future payments the Company could be required to make is represented by the contractual amount of the commitment. If the commitment were funded, the Company would be entitled to seek recovery from the customer. The Company’s policies generally require that standby letter of credit arrangements contain security and debt covenants similar to those contained in loan agreements. The fees collected in connection with the issuance of standby letters of credit are representative of the fair value of the Company's obligation undertaken in issuing the guarantee. In accordance with applicable accounting standards related to guarantees, fees collected in connection with the issuance of standby letters of credit are deferred. The fees are then recognized in income proportionately over the life of the standby letter of credit agreement. The deferred standby letter of credit fees represent the fair value of the Company's potential obligations under the standby letter of credit guarantees. The following table summarizes the above financial instruments at the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Commitments to extend credit $ 3,258,341 $ 3,337,930 Standby letters of credit 20,902 21,565 Deferred standby letter of credit fees 191 158 Loan exposures with recourse 343,314 404,532 Lease Commitments The Company leases office space, space for ATM locations, and certain branch locations under noncancelable operating leases. Several of these leases contain renewal options to extend lease terms for a period of 1 to 10 years. There has been no significant change in the future minimum lease payments payable by the Company since December 31, 2019. See the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2019 for information regarding leases and other commitments. Other Contingencies At September 30, 2020, the Bank was involved in pending lawsuits that arose in the ordinary course of business. Management has reviewed these pending lawsuits with legal counsel and has taken into consideration the view of counsel as to their outcome. In the opinion of management, the final disposition of pending lawsuits is not expected to have a material adverse effect on the Company’s financial position or results of operations. Historically, the Bank was required to maintain certain reserve requirements of vault cash and/or deposits with the Federal Reserve Bank of Boston, however the reserve requirement was reduced to zero by the Federal Reserve during the first quarter of 2020 in response to the COVID-19 pandemic, and as such, there was no reserve requirement at September 30, 2020. There was also no reserve requirement balance necessary at December 31, 2019 due to cash balances held at the Federal Reserve that were in excess of reserve requirements.

Basis of Presentation Basis of

Basis of Presentation Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting Policy	Independent Bank Corp. (the “Company”) is a state chartered, federally registered bank holding company, incorporated in 1985. The Company is the sole stockholder of Rockland Trust Company (“Rockland Trust” or the “Bank”), a Massachusetts trust company chartered in 1907. All material intercompany balances and transactions have been eliminated in consolidation. Certain previously reported amounts have been reclassified to conform to the current year’s presentation. The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation of the financial statements, primarily consisting of normal recurring adjustments, have been included. Results for the three and nine months ended September 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020 or any other interim period.

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Schedule of Equity securities gains and losses [Table Text Block]	The following table represents a summary of the gains and losses that relate to equity securities for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 Dollars in thousands Net gains (losses) recognized during the period on equity securities $ 308 $ 211 (107) 1,562 Less: net gains recognized during the period on equity securities sold during the period — — 6 6 Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting date $ 308 $ 211 $ (113) $ 1,556
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]	These available for sale securities are aggregated by major security type and length of time that individual securities have been in a continuous unrealized loss position: September 30, 2020 Less than 12 months 12 months or longer Total # of Fair Unrealized Fair Unrealized Fair Unrealized (Dollars in thousands) Agency mortgage-backed securities 2 399 (1) — — 399 (1) Agency collateralized mortgage obligations 2 27,269 (119) — — 27,269 (119) Single issuer trust preferred securities issued by banks and insurers 1 469 (20) — — 469 (20) Pooled trust preferred securities issued by banks and insurers 1 — — 1,021 (412) 1,021 (412) Total impaired available for sale securities 6 $ 28,137 $ (140) $ 1,021 $ (412) $ 29,158 $ (552)
Debt Securities, Held-to-maturity [Table Text Block]	The following table summarizes the amortized cost, fair value and allowance for credit losses of held to maturity securities and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) as of the dates indicated: September 30, 2020 December 31, 2019 Amortized Gross Gross Unrealized Allowance for credit losses Fair Amortized Gross Gross Unrealized Fair (Dollars in thousands) U.S. government agency securities $ — $ — $ — $ — $ — $ 12,874 $ 123 $ — $ 12,997 U.S. Treasury securities 4,021 79 — — 4,100 4,032 21 — 4,053 Agency mortgage-backed securities 388,106 19,687 — — 407,793 397,414 8,445 (57) 405,802 Agency collateralized mortgage obligations 237,380 9,557 — — 246,937 293,662 4,501 (849) 297,314 Single issuer trust preferred securities issued by banks 1,500 — (2) — 1,498 1,500 — (10) 1,490 Small business administration pooled securities 28,566 1,573 — — 30,139 31,324 338 (55) 31,607 Total held to maturity securities $ 659,573 $ 30,896 $ (2) $ — $ 690,467 $ 740,806 $ 13,428 $ (971) $ 753,263
Debt Securities, Held-to-maturity, Credit Quality Indicator [Table Text Block]	s of September 30, 2020, all held to maturity securities held by the Company were rated investment grade or higher.
Schedule of contractual maturities of securities [Table Text Block]	A schedule of the contractual maturities of available for sale and held to maturity securities as of September 30, 2020 is presented below: Due in one year or less Due after one year to five years Due after five to ten years Due after ten years Total Amortized Fair Amortized Fair Amortized Fair Amortized Fair Amortized Fair (Dollars in thousands) Available for sale securities U.S. government agency securities $ — $ — $ 10,001 $ 10,288 $ 12,474 $ 13,985 $ — $ — $ 22,475 $ 24,273 Agency mortgage-backed securities — — 71,624 73,773 38,956 41,956 109,570 114,891 220,150 230,620 Agency collateralized mortgage obligations — — — — — — 98,657 102,077 98,657 102,077 State, county, and municipal securities 515 516 420 422 190 207 — — 1,125 1,145 Single issuer trust preferred securities issued by banks — — — — — — 489 469 489 469 Pooled trust preferred securities issued by banks and insurers — — — — — — 1,433 1,021 1,433 1,021 Small business administration pooled securities — — — — — — 59,830 63,873 59,830 63,873 Total available for sale securities $ 515 $ 516 $ 82,045 $ 84,483 $ 51,620 $ 56,148 $ 269,979 $ 282,331 $ 404,159 $ 423,478 Held to maturity securities U.S. Treasury securities $ 1,001 $ 1,019 $ 3,020 $ 3,081 $ — $ — $ — $ — $ 4,021 $ 4,100 Agency mortgage-backed securities 8,510 8,574 1,458 1,509 53,530 56,289 324,608 341,421 388,106 407,793 Agency collateralized mortgage obligations — — — — — — 237,380 246,937 237,380 246,937 Single issuer trust preferred securities issued by banks — — — — 1,500 1,498 — — 1,500 1,498 Small business administration pooled securities — — — — — — 28,566 30,139 28,566 30,139 Total held to maturity securities $ 9,511 $ 9,593 $ 4,478 $ 4,590 $ 55,030 $ 57,787 $ 590,554 $ 618,497 $ 659,573 $ 690,467 Total $ 10,026 $ 10,109 $ 86,523 $ 89,073 $ 106,650 $ 113,935 $ 860,533 $ 900,828 $ 1,063,732 $ 1,113,945
Schedule of gross unrealized losses and fair value of investments [Table Text Block]	The following table shows the gross unrealized losses and fair value of the Company’s investments in an unrealized loss position, which the Company had not deemed to be OTTI, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2019: December 31, 2019 Less than 12 months 12 months or longer Total # of Fair Unrealized Fair Unrealized Fair Unrealized (Dollars in thousands) Agency mortgage-backed securities 12 34,009 (59) 243 (2) 34,252 (61) Agency collateralized mortgage obligations 17 48,476 (215) 37,382 (653) 85,858 (868) Single issuer trust preferred securities issued by banks and insurers 1 — — 1,490 (10) 1,490 (10) Pooled trust preferred securities issued by banks and insurers 1 — — 1,114 (374) 1,114 (374) Small business administration pooled securities 1 7,349 (55) — — 7,349 (55) Total temporarily impaired securities 32 $ 89,834 $ (329) $ 40,229 $ (1,039) $ 130,063 $ (1,368)
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]	The following table summarizes the amortized cost, allowance for credit losses, and fair value of available for sale securities and the corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) as of the dates indicated: September 30, 2020 December 31, 2019 Amortized Gross Gross Unrealized Allowance for credit losses Fair Amortized Gross Gross Unrealized Fair (Dollars in thousands) U.S. government agency securities $ 22,475 $ 1,798 $ — $ — $ 24,273 $ 32,473 $ 642 $ — $ 33,115 Agency mortgage-backed securities 220,150 10,471 (1) — 230,620 243,548 3,456 (4) 247,000 Agency collateralized mortgage obligations 98,657 3,539 (119) — 102,077 87,305 1,225 (19) 88,511 State, county, and municipal securities 1,125 20 — — 1,145 1,377 19 — 1,396 Single issuer trust preferred securities issued by banks 489 — (20) — 469 488 5 — 493 Pooled trust preferred securities issued by banks and insurers 1,433 — (412) — 1,021 1,488 — (374) 1,114 Small business administration pooled securities 59,830 4,043 — — 63,873 54,024 771 — 54,795 Total available for sale securities $ 404,159 $ 19,871 $ (552) $ — $ 423,478 $ 420,703 $ 6,118 $ (397) $ 426,424

Loans, Allowance for Credit L_2

Loans, Allowance for Credit Losses and Credit Quality (Tables)	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Financing Receivable, Allowance for Credit Loss [Table Text Block]	The following table summarizes the change in allowance for credit losses by loan category, and bifurcates the amount of loans allocated to each loan category for the period indicated: Three Months Ended September 30, 2020 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for credit losses Beginning balance $ 25,662 $ 36,956 $ 4,501 $ 4,561 $ 15,046 $ 24,860 $ 590 $ 112,176 Charge-offs (185) (3,885) — (49) — — (185) (4,304) Recoveries 1 9 — 2 1 21 219 253 Provision for credit loss expense 2,741 6,306 709 79 (884) (1,309) (142) 7,500 Ending balance (1) $ 28,219 $ 39,386 $ 5,210 $ 4,593 $ 14,163 $ 23,572 $ 482 $ 115,625 Nine Months Ended September 30, 2020 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for credit losses Beginning balance, pre adoption of Topic 326 $ 17,594 $ 32,935 $ 6,053 $ 1,746 $ 3,440 $ 5,576 $ 396 $ 67,740 Cumulative effect accounting adjustment (2) (1,984) (13,048) (3,652) 495 9,828 7,012 212 (1,137) Cumulative effect accounting adjustment (3) 49 337 — — 423 319 29 1,157 Charge-offs (185) (3,885) — (194) — (142) (1,342) (5,748) Recoveries 47 9 — 8 2 174 873 1,113 Provision for credit loss expense 12,698 23,038 2,809 2,538 470 10,633 314 52,500 Ending balance (1) $ 28,219 $ 39,386 $ 5,210 $ 4,593 $ 14,163 $ 23,572 $ 482 $ 115,625 (1) Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $36.7 million as of September 30, 2020. (2) Represents adjustment needed to reflect the cumulative day one impact pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.1 million decrease to the allowance attributable to the change in accounting methodology for estimating the allowance for credit losses resulting from the Company's adoption of the standard. (3) Represents adjustment needed to reflect the day one reclassification of the Company's PCI loan balances to PCD and the associated gross-up, pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.2 million increase to the allowance resulting from the day one reclassification. Three Months Ended September 30, 2019 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for loan losses Beginning balance $ 16,857 $ 32,660 $ 5,593 $ 1,768 $ 3,296 $ 5,547 $ 239 $ 65,960 Charge-offs — (82) — (125) — (28) (472) (707) Recoveries 1,003 106 — 61 140 194 185 1,689 Provision (benefit) (528) (33) 240 48 (88) 36 325 — Ending balance $ 17,332 $ 32,651 $ 5,833 $ 1,752 $ 3,348 $ 5,749 $ 277 $ 66,942 Nine Months Ended September 30, 2019 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for loan losses Beginning balance $ 15,760 $ 32,370 $ 5,158 $ 1,756 $ 3,219 $ 5,608 $ 422 $ 64,293 Charge-offs — (82) — (319) — (212) (1,125) (1,738) Recoveries 1,127 152 — 108 141 278 581 2,387 Provision (benefit) 445 211 675 207 (12) 75 399 2,000 Ending balance $ 17,332 $ 32,651 $ 5,833 $ 1,752 $ 3,348 $ 5,749 $ 277 $ 66,942 Ending balance: collectively evaluated for impairment $ 17,326 $ 32,610 $ 5,833 $ 1,741 $ 2,729 $ 5,594 $ 272 $ 66,105 Ending balance: individually evaluated for impairment $ 6 $ 41 $ — $ 11 $ 619 $ 155 $ 5 $ 837
Financing Receivable Credit Quality Indicators [Table Text Block]	he following table details the amortized cost balances of the Company's loan portfolios, presented by credit quality indicator and origination year as of the date indicated below: September 30, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving converted to Term Total (Dollars in thousands) Commercial and Pass $ 1,012,974 (1) $ 153,137 $ 107,318 $ 34,826 $ 23,065 $ 22,334 $ 601,937 $ 2,577 $ 1,958,168 Potential weakness 2,560 2,302 7,833 4,573 1,219 318 15,248 50 34,103 Definite weakness - loss unlikely 2,732 1,553 22,748 5,500 2,483 1,419 33,496 — 69,931 Partial loss probable — — — — — 143 — — 143 Definite loss — — — — — — — — — Total commercial and industrial $ 1,018,266 $ 156,992 $ 137,899 $ 44,899 $ 26,767 $ 24,214 $ 650,681 $ 2,627 $ 2,062,345 Commercial real estate Pass $ 753,415 $ 859,548 $ 512,371 $ 587,345 $ 399,442 $ 751,629 $ 39,998 $ 16,341 $ 3,920,089 Potential weakness 20,639 15,957 20,313 7,941 27,253 47,875 — — 139,978 Definite weakness - loss unlikely 4,261 2,265 10,092 21,081 2,170 6,605 — — 46,474 Partial loss probable — — 18,923 — — — — — 18,923 Definite loss — — — — — — — — — Total commercial real estate $ 778,315 $ 877,770 $ 561,699 $ 616,367 $ 428,865 $ 806,109 $ 39,998 $ 16,341 $ 4,125,464 Commercial construction Pass $ 182,291 $ 196,420 $ 73,298 $ 66,406 $ — $ 6,750 $ 31,372 $ 1,077 $ 557,614 Potential weakness — 9,352 5,037 — — — 328 — 14,717 Definite weakness - loss unlikely — — 1,003 — — — — — 1,003 Partial loss probable — — — — — — — — — Definite loss — — — — — — — — — Total commercial construction $ 182,291 $ 205,772 $ 79,338 $ 66,406 $ — $ 6,750 $ 31,700 $ 1,077 $ 573,334 Small business Pass $ 27,457 $ 28,766 $ 20,806 $ 14,627 $ 14,528 $ 22,644 $ 34,569 $ — $ 163,397 Potential weakness — 10 16 10 755 232 736 — 1,759 Definite weakness - loss unlikely 184 408 78 170 98 723 786 — 2,447 Partial loss probable — — — — — — 29 — 29 Definite loss — — — — — — — — — Total small business $ 27,641 $ 29,184 $ 20,900 $ 14,807 $ 15,381 $ 23,599 $ 36,120 $ — $ 167,632 Residential real estate Pass $ 131,691 $ 167,901 $ 187,194 $ 168,048 $ 241,638 $ 449,219 $ — $ — $ 1,345,691 Default 728 — 760 235 167 4,724 — — 6,614 Total residential real estate $ 132,419 $ 167,901 $ 187,954 $ 168,283 $ 241,805 $ 453,943 $ — $ — $ 1,352,305 Home equity Pass $ 60,274 $ 66,238 $ 59,534 $ 59,387 $ 44,817 $ 122,397 $ 681,784 $ 4,057 $ 1,098,488 Default — — — — — 455 2,044 67 2,566 Total home equity $ 60,274 $ 66,238 $ 59,534 $ 59,387 $ 44,817 $ 122,852 $ 683,828 $ 4,124 $ 1,101,054 Other consumer Pass $ 679 $ 450 $ 209 $ 739 $ 696 $ 7,737 $ 12,493 $ — $ 23,003 Default — — — 20 — 34 2 — 56 Total other consumer $ 679 $ 450 $ 209 $ 759 $ 696 $ 7,771 $ 12,495 $ — $ 23,059 Total $ 2,199,885 $ 1,504,307 $ 1,047,533 $ 970,908 $ 758,331 $ 1,445,238 $ 1,454,822 $ 24,169 $ 9,405,193 The following tables detail the amount of outstanding principal balances relative to each of the risk-rating categories for the Company’s loan portfolio as of December 31, 2019: December 31, 2019 Category Risk Commercial and Commercial Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 1,274,155 $ 3,860,555 $ 542,608 $ 171,213 $ 5,848,531 Potential weakness 7 63,485 97,268 2,247 1,416 164,416 Definite weakness-loss unlikely 8 57,396 44,536 2,438 1,868 106,238 Partial loss probable 9 — — — — — Definite loss 10 — — — — — Total $ 1,395,036 $ 4,002,359 $ 547,293 $ 174,497 $ 6,119,185
Foreclosed Residential Real Estate Property [Table Text Block]	The following table shows information regarding foreclosed residential real estate property at the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Foreclosed residential real estate property held by the creditor $ — $ — Recorded investment in mortgage loans collateralized by residential real estate property that are in the process of foreclosure $ 2,113 $ 3,294
Financing Receivable Credit Quality Indicators For Consumer And Residential Portfolio Table Text Block	The following table shows the weighted average FICO scores and the weighted average combined LTV ratios at the dates indicated below: September 30 December 31 Residential portfolio FICO score (re-scored)(1) 749 749 LTV (re-valued)(2) 57.7 % 59.0 % Home equity portfolio FICO score (re-scored)(1) 770 767 LTV (re-valued)(2)(3) 46.6 % 46.6 % (1) The average FICO scores at September 30, 2020 are based upon rescores available from August 2020 and origination score data for loans booked in September 2020. The average FICO scores at December 31, 2019 were based upon rescores available from November 2019 and origination score data for loans booked in December 2019. (2) The combined LTV ratios for September 30, 2020 are based upon updated automated valuations as of August 2020, when available, and/or the most current valuation data available. The combined LTV ratios for December 31, 2019 were based upon updated automated valuations as of November 2019, when available, and/or the most current valuation data available as of such date. The updated automated valuations provide new information on loans that may be available since the previous valuation was obtained. If no new information is available, the valuation will default to the previously obtained data or most recent appraisal. (3) For home equity loans and lines in a subordinate lien, the LTV data represents a combined LTV, taking into account the senior lien data for loans and lines.
Financing Receivable, Past Due [Table Text Block]	The following tables show the age analysis of past due financing receivables as of the dates indicated: September 30, 2020 30-59 days 60-89 days 90 days or more Total Past Due Total Amortized Cost Number Principal Number Principal Number Principal Number Principal Current (Dollars in thousands) Loan Portfolio Commercial and industrial 1 $ 52 6 $ 3,608 5 $ 930 12 $ 4,590 $ 2,057,755 $ 2,062,345 $ — Commercial real estate 1 99 2 8,269 5 1,355 8 9,723 4,115,741 4,125,464 — Commercial construction — — — — — — — — 573,334 573,334 — Small business 6 514 4 455 12 124 22 1,093 166,539 167,632 — Residential real estate 11 1,792 7 1,631 37 5,870 55 9,293 1,343,012 1,352,305 — Home equity 18 1,581 8 468 36 2,566 62 4,615 1,096,439 1,101,054 — Other consumer (1) 237 217 3 1 12 57 252 275 22,784 23,059 1 Total 274 $ 4,255 30 $ 14,432 107 $ 10,902 411 $ 29,589 $ 9,375,604 $ 9,405,193 $ 1 December 31, 2019 30-59 days 60-89 days 90 days or more Total Past Due Total Recorded Number Principal Number Principal Number Principal Number Principal Current (Dollars in thousands) Loan Portfolio Commercial and industrial 1 $ 253 2 $ 323 5 $ 760 8 $ 1,336 $ 1,393,700 $ 1,395,036 $ — Commercial real estate 7 1,690 1 194 8 2,038 16 3,922 3,998,437 4,002,359 218 (2) Commercial construction 1 560 — — — — 1 560 546,733 547,293 — Small business 11 837 3 15 6 115 20 967 173,530 174,497 — Residential real estate 17 2,237 17 3,055 38 7,020 72 12,312 1,578,257 1,590,569 1,652 (2) Home equity 23 1,689 8 524 40 3,854 71 6,067 1,127,731 1,133,798 265 (2) Other consumer (1) 387 245 12 44 16 32 415 321 29,766 30,087 22 Total 447 $ 7,511 43 $ 4,155 113 $ 13,819 603 $ 25,485 $ 8,848,154 $ 8,873,639 $ 2,157 (1) Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances. (2) Represents purchased credit impaired ("PCI") loans that were accruing interest due to expectations of future cash collections.
Financing Receivable, Nonaccrual [Table Text Block]	The following table shows information regarding nonaccrual loans as of the dates indicated: Nonaccrual Balances September 30, 2020 December 31, 2019 With Allowance for Credit Losses Without Allowance for Credit Losses Total Total (Dollars in thousands) Commercial and industrial $ 17,816 $ 19,035 $ 36,851 $ 22,574 Commercial real estate 17,501 20,663 38,164 3,016 Small business 542 — 542 311 Residential real estate 13,379 2,850 16,229 13,360 Home equity 6,052 107 6,159 6,570 Other consumer 79 — 79 61 Total nonaccrual loans (1) $ 55,369 $ 42,655 $ 98,024 $ 45,892
Financing Receivable, Troubled Debt Restructuring [Table Text Block]	The following table shows the Company’s total TDRs and other pertinent information as of the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) TDRs on accrual status $ 17,521 $ 19,599 TDRs on nonaccrual 23,810 24,766 Total TDRs $ 41,331 $ 44,365 Amount of specific reserves associated with TDRs n/a $ 855 Additional commitments to lend to a borrower who has been a party to a TDR $ 158 $ 63
Schedule of Debtor Troubled Debt Restructuring, Subsequent Periods [Table Text Block]	The following table shows the troubled debt restructurings which occurred during the periods indicated and the change in the recorded investment subsequent to the modifications occurring: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 2 $ 83 $ 83 5 $ 391 $ 391 Commercial real estate 3 744 744 8 2,518 2,518 Small business — — — 2 112 88 Residential real estate — — — 2 559 642 Total 5 $ 827 $ 827 17 $ 3,580 $ 3,639 Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 1 $ 87 $ 87 2 $ 184 $ 184 Commercial real estate 1 133 133 2 283 283 Small business 1 19 19 2 33 33 Residential real estate 1 163 168 1 163 168 Home equity 1 46 46 2 121 121 Total 5 $ 448 $ 453 9 $ 784 $ 789
Troubled Debt Restructurings On Financing Receivables Post Modifications Table Text Block	Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 1 $ 87 $ 87 2 $ 184 $ 184 Commercial real estate 1 133 133 2 283 283 Small business 1 19 19 2 33 33 Residential real estate 1 163 168 1 163 168 Home equity 1 46 46 2 121 121 Total 5 $ 448 $ 453 9 $ 784 $ 789 The following table shows the Company’s post-modification balance of TDRs listed by type of modification for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands) Adjusted interest rate 218 — $ 822 $ 150 Court ordered concession — — 25 75 Extended maturity 609 453 2,792 606 Total 827 453 $ 3,639 $ 831

Loans, Allowance for Loan Los_2

Loans, Allowance for Loan Losses and Credit Quality (Tables)	9 Months Ended
	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Tabular disclosure of financing receivables bifurcated by type of impairment evaluation [Table Text Block]	The following table bifurcates the amount of loans and the allowance allocated to each loan category based on the type of impairment analysis as of December 31, 2019: December 31, 2019 Commercial Commercial Commercial Small Residential Home Other Consumer Total (Dollars in thousands) Financing receivables ending balance: Collectively evaluated for impairment $ 1,370,580 $ 3,987,848 $ 547,293 $ 173,960 $ 1,571,848 $ 1,127,963 $ 29,663 $ 8,809,155 Individually evaluated for impairment 24,456 8,337 — 537 11,228 4,948 122 49,628 Purchased credit impaired loans — 6,174 — — 7,493 887 302 14,856 Total loans by group $ 1,395,036 $ 4,002,359 $ 547,293 $ 174,497 $ 1,590,569 $ 1,133,798 $ 30,087 $ 8,873,639 (1) (1) The amount of net deferred costs on originated loans included in the ending balance was $7.1 million at December 31, 2019. Net unamortized discounts on acquired loans not deemed to be purchased credit impaired ("PCI") included in the ending balance was $21.6 million at December 31, 2019.
Summary of changes in allowance for loan losses	The following table summarizes the change in allowance for credit losses by loan category, and bifurcates the amount of loans allocated to each loan category for the period indicated: Three Months Ended September 30, 2020 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for credit losses Beginning balance $ 25,662 $ 36,956 $ 4,501 $ 4,561 $ 15,046 $ 24,860 $ 590 $ 112,176 Charge-offs (185) (3,885) — (49) — — (185) (4,304) Recoveries 1 9 — 2 1 21 219 253 Provision for credit loss expense 2,741 6,306 709 79 (884) (1,309) (142) 7,500 Ending balance (1) $ 28,219 $ 39,386 $ 5,210 $ 4,593 $ 14,163 $ 23,572 $ 482 $ 115,625 Nine Months Ended September 30, 2020 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for credit losses Beginning balance, pre adoption of Topic 326 $ 17,594 $ 32,935 $ 6,053 $ 1,746 $ 3,440 $ 5,576 $ 396 $ 67,740 Cumulative effect accounting adjustment (2) (1,984) (13,048) (3,652) 495 9,828 7,012 212 (1,137) Cumulative effect accounting adjustment (3) 49 337 — — 423 319 29 1,157 Charge-offs (185) (3,885) — (194) — (142) (1,342) (5,748) Recoveries 47 9 — 8 2 174 873 1,113 Provision for credit loss expense 12,698 23,038 2,809 2,538 470 10,633 314 52,500 Ending balance (1) $ 28,219 $ 39,386 $ 5,210 $ 4,593 $ 14,163 $ 23,572 $ 482 $ 115,625 (1) Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $36.7 million as of September 30, 2020. (2) Represents adjustment needed to reflect the cumulative day one impact pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.1 million decrease to the allowance attributable to the change in accounting methodology for estimating the allowance for credit losses resulting from the Company's adoption of the standard. (3) Represents adjustment needed to reflect the day one reclassification of the Company's PCI loan balances to PCD and the associated gross-up, pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment represents a $1.2 million increase to the allowance resulting from the day one reclassification. Three Months Ended September 30, 2019 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for loan losses Beginning balance $ 16,857 $ 32,660 $ 5,593 $ 1,768 $ 3,296 $ 5,547 $ 239 $ 65,960 Charge-offs — (82) — (125) — (28) (472) (707) Recoveries 1,003 106 — 61 140 194 185 1,689 Provision (benefit) (528) (33) 240 48 (88) 36 325 — Ending balance $ 17,332 $ 32,651 $ 5,833 $ 1,752 $ 3,348 $ 5,749 $ 277 $ 66,942 Nine Months Ended September 30, 2019 (Dollars in thousands) Commercial and Commercial Commercial Small Residential Other Consumer Total Allowance for loan losses Beginning balance $ 15,760 $ 32,370 $ 5,158 $ 1,756 $ 3,219 $ 5,608 $ 422 $ 64,293 Charge-offs — (82) — (319) — (212) (1,125) (1,738) Recoveries 1,127 152 — 108 141 278 581 2,387 Provision (benefit) 445 211 675 207 (12) 75 399 2,000 Ending balance $ 17,332 $ 32,651 $ 5,833 $ 1,752 $ 3,348 $ 5,749 $ 277 $ 66,942 Ending balance: collectively evaluated for impairment $ 17,326 $ 32,610 $ 5,833 $ 1,741 $ 2,729 $ 5,594 $ 272 $ 66,105 Ending balance: individually evaluated for impairment $ 6 $ 41 $ — $ 11 $ 619 $ 155 $ 5 $ 837
Internal risk-rating categories for the Company's commercial portfolio	he following table details the amortized cost balances of the Company's loan portfolios, presented by credit quality indicator and origination year as of the date indicated below: September 30, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving converted to Term Total (Dollars in thousands) Commercial and Pass $ 1,012,974 (1) $ 153,137 $ 107,318 $ 34,826 $ 23,065 $ 22,334 $ 601,937 $ 2,577 $ 1,958,168 Potential weakness 2,560 2,302 7,833 4,573 1,219 318 15,248 50 34,103 Definite weakness - loss unlikely 2,732 1,553 22,748 5,500 2,483 1,419 33,496 — 69,931 Partial loss probable — — — — — 143 — — 143 Definite loss — — — — — — — — — Total commercial and industrial $ 1,018,266 $ 156,992 $ 137,899 $ 44,899 $ 26,767 $ 24,214 $ 650,681 $ 2,627 $ 2,062,345 Commercial real estate Pass $ 753,415 $ 859,548 $ 512,371 $ 587,345 $ 399,442 $ 751,629 $ 39,998 $ 16,341 $ 3,920,089 Potential weakness 20,639 15,957 20,313 7,941 27,253 47,875 — — 139,978 Definite weakness - loss unlikely 4,261 2,265 10,092 21,081 2,170 6,605 — — 46,474 Partial loss probable — — 18,923 — — — — — 18,923 Definite loss — — — — — — — — — Total commercial real estate $ 778,315 $ 877,770 $ 561,699 $ 616,367 $ 428,865 $ 806,109 $ 39,998 $ 16,341 $ 4,125,464 Commercial construction Pass $ 182,291 $ 196,420 $ 73,298 $ 66,406 $ — $ 6,750 $ 31,372 $ 1,077 $ 557,614 Potential weakness — 9,352 5,037 — — — 328 — 14,717 Definite weakness - loss unlikely — — 1,003 — — — — — 1,003 Partial loss probable — — — — — — — — — Definite loss — — — — — — — — — Total commercial construction $ 182,291 $ 205,772 $ 79,338 $ 66,406 $ — $ 6,750 $ 31,700 $ 1,077 $ 573,334 Small business Pass $ 27,457 $ 28,766 $ 20,806 $ 14,627 $ 14,528 $ 22,644 $ 34,569 $ — $ 163,397 Potential weakness — 10 16 10 755 232 736 — 1,759 Definite weakness - loss unlikely 184 408 78 170 98 723 786 — 2,447 Partial loss probable — — — — — — 29 — 29 Definite loss — — — — — — — — — Total small business $ 27,641 $ 29,184 $ 20,900 $ 14,807 $ 15,381 $ 23,599 $ 36,120 $ — $ 167,632 Residential real estate Pass $ 131,691 $ 167,901 $ 187,194 $ 168,048 $ 241,638 $ 449,219 $ — $ — $ 1,345,691 Default 728 — 760 235 167 4,724 — — 6,614 Total residential real estate $ 132,419 $ 167,901 $ 187,954 $ 168,283 $ 241,805 $ 453,943 $ — $ — $ 1,352,305 Home equity Pass $ 60,274 $ 66,238 $ 59,534 $ 59,387 $ 44,817 $ 122,397 $ 681,784 $ 4,057 $ 1,098,488 Default — — — — — 455 2,044 67 2,566 Total home equity $ 60,274 $ 66,238 $ 59,534 $ 59,387 $ 44,817 $ 122,852 $ 683,828 $ 4,124 $ 1,101,054 Other consumer Pass $ 679 $ 450 $ 209 $ 739 $ 696 $ 7,737 $ 12,493 $ — $ 23,003 Default — — — 20 — 34 2 — 56 Total other consumer $ 679 $ 450 $ 209 $ 759 $ 696 $ 7,771 $ 12,495 $ — $ 23,059 Total $ 2,199,885 $ 1,504,307 $ 1,047,533 $ 970,908 $ 758,331 $ 1,445,238 $ 1,454,822 $ 24,169 $ 9,405,193 The following tables detail the amount of outstanding principal balances relative to each of the risk-rating categories for the Company’s loan portfolio as of December 31, 2019: December 31, 2019 Category Risk Commercial and Commercial Commercial Small Business Total (Dollars in thousands) Pass 1 - 6 $ 1,274,155 $ 3,860,555 $ 542,608 $ 171,213 $ 5,848,531 Potential weakness 7 63,485 97,268 2,247 1,416 164,416 Definite weakness-loss unlikely 8 57,396 44,536 2,438 1,868 106,238 Partial loss probable 9 — — — — — Definite loss 10 — — — — — Total $ 1,395,036 $ 4,002,359 $ 547,293 $ 174,497 $ 6,119,185
Weighted average FICO scores and the weighted average combined LTV ratio	The following table shows the weighted average FICO scores and the weighted average combined LTV ratios at the dates indicated below: September 30 December 31 Residential portfolio FICO score (re-scored)(1) 749 749 LTV (re-valued)(2) 57.7 % 59.0 % Home equity portfolio FICO score (re-scored)(1) 770 767 LTV (re-valued)(2)(3) 46.6 % 46.6 % (1) The average FICO scores at September 30, 2020 are based upon rescores available from August 2020 and origination score data for loans booked in September 2020. The average FICO scores at December 31, 2019 were based upon rescores available from November 2019 and origination score data for loans booked in December 2019. (2) The combined LTV ratios for September 30, 2020 are based upon updated automated valuations as of August 2020, when available, and/or the most current valuation data available. The combined LTV ratios for December 31, 2019 were based upon updated automated valuations as of November 2019, when available, and/or the most current valuation data available as of such date. The updated automated valuations provide new information on loans that may be available since the previous valuation was obtained. If no new information is available, the valuation will default to the previously obtained data or most recent appraisal. (3) For home equity loans and lines in a subordinate lien, the LTV data represents a combined LTV, taking into account the senior lien data for loans and lines.
Summary of nonaccrual loans	The following table shows information regarding nonaccrual loans as of the dates indicated: Nonaccrual Balances September 30, 2020 December 31, 2019 With Allowance for Credit Losses Without Allowance for Credit Losses Total Total (Dollars in thousands) Commercial and industrial $ 17,816 $ 19,035 $ 36,851 $ 22,574 Commercial real estate 17,501 20,663 38,164 3,016 Small business 542 — 542 311 Residential real estate 13,379 2,850 16,229 13,360 Home equity 6,052 107 6,159 6,570 Other consumer 79 — 79 61 Total nonaccrual loans (1) $ 55,369 $ 42,655 $ 98,024 $ 45,892
Foreclosed Residential Real Estate Property [Table Text Block]	The following table shows information regarding foreclosed residential real estate property at the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Foreclosed residential real estate property held by the creditor $ — $ — Recorded investment in mortgage loans collateralized by residential real estate property that are in the process of foreclosure $ 2,113 $ 3,294
Age analysis of past due financing receivables	The following tables show the age analysis of past due financing receivables as of the dates indicated: September 30, 2020 30-59 days 60-89 days 90 days or more Total Past Due Total Amortized Cost Number Principal Number Principal Number Principal Number Principal Current (Dollars in thousands) Loan Portfolio Commercial and industrial 1 $ 52 6 $ 3,608 5 $ 930 12 $ 4,590 $ 2,057,755 $ 2,062,345 $ — Commercial real estate 1 99 2 8,269 5 1,355 8 9,723 4,115,741 4,125,464 — Commercial construction — — — — — — — — 573,334 573,334 — Small business 6 514 4 455 12 124 22 1,093 166,539 167,632 — Residential real estate 11 1,792 7 1,631 37 5,870 55 9,293 1,343,012 1,352,305 — Home equity 18 1,581 8 468 36 2,566 62 4,615 1,096,439 1,101,054 — Other consumer (1) 237 217 3 1 12 57 252 275 22,784 23,059 1 Total 274 $ 4,255 30 $ 14,432 107 $ 10,902 411 $ 29,589 $ 9,375,604 $ 9,405,193 $ 1 December 31, 2019 30-59 days 60-89 days 90 days or more Total Past Due Total Recorded Number Principal Number Principal Number Principal Number Principal Current (Dollars in thousands) Loan Portfolio Commercial and industrial 1 $ 253 2 $ 323 5 $ 760 8 $ 1,336 $ 1,393,700 $ 1,395,036 $ — Commercial real estate 7 1,690 1 194 8 2,038 16 3,922 3,998,437 4,002,359 218 (2) Commercial construction 1 560 — — — — 1 560 546,733 547,293 — Small business 11 837 3 15 6 115 20 967 173,530 174,497 — Residential real estate 17 2,237 17 3,055 38 7,020 72 12,312 1,578,257 1,590,569 1,652 (2) Home equity 23 1,689 8 524 40 3,854 71 6,067 1,127,731 1,133,798 265 (2) Other consumer (1) 387 245 12 44 16 32 415 321 29,766 30,087 22 Total 447 $ 7,511 43 $ 4,155 113 $ 13,819 603 $ 25,485 $ 8,848,154 $ 8,873,639 $ 2,157 (1) Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances. (2) Represents purchased credit impaired ("PCI") loans that were accruing interest due to expectations of future cash collections.
Summary of Troubled Debt Restructuring and other pertinent information	The following table shows the Company’s total TDRs and other pertinent information as of the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) TDRs on accrual status $ 17,521 $ 19,599 TDRs on nonaccrual 23,810 24,766 Total TDRs $ 41,331 $ 44,365 Amount of specific reserves associated with TDRs n/a $ 855 Additional commitments to lend to a borrower who has been a party to a TDR $ 158 $ 63
Change in investment recorded subsequent to modifications	The following table shows the troubled debt restructurings which occurred during the periods indicated and the change in the recorded investment subsequent to the modifications occurring: Three Months Ended Nine Months Ended September 30, 2020 September 30, 2020 Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 2 $ 83 $ 83 5 $ 391 $ 391 Commercial real estate 3 744 744 8 2,518 2,518 Small business — — — 2 112 88 Residential real estate — — — 2 559 642 Total 5 $ 827 $ 827 17 $ 3,580 $ 3,639 Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 1 $ 87 $ 87 2 $ 184 $ 184 Commercial real estate 1 133 133 2 283 283 Small business 1 19 19 2 33 33 Residential real estate 1 163 168 1 163 168 Home equity 1 46 46 2 121 121 Total 5 $ 448 $ 453 9 $ 784 $ 789
Post modification balance of Troubled Debt Restructuring	Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Number of Pre-Modification Post-Modification Number of Pre-Modification Post-Modification (Dollars in thousands) Troubled debt restructurings Commercial and industrial 1 $ 87 $ 87 2 $ 184 $ 184 Commercial real estate 1 133 133 2 283 283 Small business 1 19 19 2 33 33 Residential real estate 1 163 168 1 163 168 Home equity 1 46 46 2 121 121 Total 5 $ 448 $ 453 9 $ 784 $ 789 The following table shows the Company’s post-modification balance of TDRs listed by type of modification for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands) Adjusted interest rate 218 — $ 822 $ 150 Court ordered concession — — 25 75 Extended maturity 609 453 2,792 606 Total 827 453 $ 3,639 $ 831
Impaired loans by loan portfolio	The table below sets forth information regarding the Company’s impaired loans by loan portfolio at the date indicated: December 31, 2019 Recorded Unpaid Related (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 23,786 $ 34,970 $ — Commercial real estate 6,213 12,101 — Small business 469 484 — Residential real estate 4,976 5,123 — Home equity 3,764 3,893 — Other consumer 34 34 — Subtotal 39,242 56,605 — With an allowance recorded Commercial and industrial $ 670 $ 670 $ 126 Commercial real estate 2,124 2,124 48 Small business 68 105 8 Residential real estate 6,252 7,163 637 Home equity 1,184 1,382 156 Other consumer 88 91 5 Subtotal 10,386 11,535 980 Total $ 49,628 $ 68,140 $ 980
Interest income recognized on impaired loans	The following table sets forth information regarding interest income recognized on impaired loans, by portfolio, for the periods indicated: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Average Interest Average Interest (Dollars in thousands) With no related allowance recorded Commercial and industrial $ 25,694 $ 35 $ 27,937 $ 108 Commercial real estate 12,987 149 13,261 478 Small business 235 3 266 10 Residential real estate 5,031 57 5,061 175 Home equity 4,417 50 4,479 151 Other consumer 39 1 43 2 Subtotal 48,403 295 51,047 924 With an allowance recorded Commercial and industrial $ 353 $ 4 $ 360 $ 13 Commercial real estate 1,402 20 1,415 60 Small business 92 — 95 2 Residential real estate 6,047 61 6,115 179 Home equity 959 11 972 33 Other consumer 107 1 116 3 Subtotal 8,960 97 9,073 290 Total $ 57,363 $ 392 $ 60,120 $ 1,214
Certain Loans Acquired In Transfer Accounted For As Debt Securities Acquired During Period	The following table displays certain information pertaining to PCI loans at the date indicated: December 31, 2019 (Dollars in thousands) Outstanding balance $ 18,358 Carrying amount $ 14,856
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule	The following table summarizes activity in the accretable yield for the PCI loan portfolio for the periods indicated: Three Months Ended September 30 Nine Months Ended September 30 2019 2019 (Dollars in thousands) Beginning balance $ 2,238 $ 1,191 Acquisition — 1,464 Accretion (412) (1,215) Other change in expected cash flows (1) 237 623 Reclassification from nonaccretable difference for loans which have paid off 227 227 Ending balance $ 2,290 $ 2,290

Goodwill Goodwill (Tables)

Goodwill Goodwill (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill [Table Text Block]	The following table sets forth the carrying value of goodwill and other intangible assets, net of accumulated amortization, at the dates indicated below: September 30, 2020 December 31, 2019 (Dollars in thousands) Balances not subject to amortization Goodwill $ 506,206 $ 506,206 Balances subject to amortization Core deposit intangibles 23,625 28,016 Other intangible assets 918 1,270 Total other intangible assets 24,543 29,286 Total goodwill and other intangible assets $ 530,749 $ 535,492

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Summary of earnings per share	Earnings per share consisted of the following components for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands, except per share data) Net income $ 34,873 $ 51,845 $ 86,526 $ 117,698 Weighted Average Shares Basic shares 32,951,918 34,361,176 33,358,879 32,283,196 Effect of dilutive securities 24,758 39,390 27,871 45,416 Diluted shares 32,976,676 34,400,566 33,386,750 32,328,612 Net income per share Basic EPS $ 1.06 $ 1.51 $ 2.59 $ 3.65 Effect of dilutive securities — — — (0.01) Diluted EPS $ 1.06 $ 1.51 $ 2.59 $ 3.64
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	As a result of the anti-dilution, the potential common shares excluded from the calculation of diluted earnings per share are as follows: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 Stock options 10,000 5,000 10,000 — Performance-based restricted stock — — 11,080 —

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]	During the nine months ended September 30, 2020, the Company made the following awards of time vested restricted stock: Date Shares Granted Plan Grant Date Fair Value Per Share Vesting Period 2/27/2020 46,550 2005 Employee Stock Plan $ 70.24 Ratably over 5 years from grant date 4/15/2020 880 2005 Employee Stock Plan $ 68.14 Ratably over 5 years from grant date 5/27/2020 9,438 2018 Non-Employee Director Stock Plan $ 72.86 Shares vested immediately
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	The Company did not grant any awards of options to purchase shares of common stock during the nine months ended September 30, 2020.

Derivatives and Hedging Activit

Derivatives and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes	The following tables reflect the Company's derivative positions as of the dates indicated below for interest rate derivatives which qualify as cash flow hedges for accounting purposes: September 30, 2020 Weighted Average Rate Notional Amount Average Maturity Current Pay Fixed Fair Value (1) (in thousands) (in years) (in thousands) Interest rate swaps on borrowings $ 75,000 1.43 0.26 % 1.53 % $ (1,561) Current Rate Paid Receive Fixed Interest rate swaps on loans 450,000 2.91 0.15 % 2.37 % 29,878 Current Rate Paid Receive Fixed Swap Rate Interest rate collars on loans 400,000 2.91 0.15 % 2.73% - 2.20% 24,169 Total $ 925,000 $ 52,486 December 31, 2019 Weighted Average Rate Notional Amount Average Maturity Current Pay Fixed Fair Value (1) (in thousands) (in years) (in thousands) Interest rate swaps on borrowings $ 75,000 2.18 1.90 % 1.53 % $ 140 Current Rate Paid Receive Fixed Interest rate swaps on loans 450,000 3.66 1.76 % 2.37 % 12,907 Current Rate Paid Receive Fixed Swap Rate Interest rate collars on loans 400,000 3.66 1.76 % 2.73% - 2.20% 9,896 Total $ 925,000 $ 22,943
Summary of customer related derivative positions, not designated as hedging	Notional Amount Maturing Number of Positions Less than 1 year Less than 2 years Less than 3 years Less than 4 years Thereafter Total Fair Value (2) September 30, 2020 (Dollars in thousands) Loan level swaps Receive fixed, pay variable 331 $ 135,993 $ 34,017 $ 158,477 $ 138,314 $ 1,260,159 $ 1,726,960 $ 145,517 Pay fixed, receive variable 322 $ 135,993 $ 34,017 $ 158,477 $ 138,314 $ 1,260,159 $ 1,726,960 $ (145,501) Foreign exchange contracts Buys foreign currency, sells U.S. currency 33 $ 81,207 $ — $ — $ — $ — $ 81,207 $ (3,125) Buys U.S. currency, sells foreign currency 33 $ 81,207 $ — $ — $ — $ — $ 81,207 $ 3,151 Risk participation agreements Participation out 13 $ 6,800 $ — $ 7,282 $ — $ 112,487 $ 126,569 $ 745 Participation in 10 $ — $ 18,978 $ 23,925 $ 36,836 $ 18,295 $ 98,034 $ (269) Notional Amount Maturing Number of Positions Less than 1 year Less than 2 years Less than 3 years Less than 4 years Thereafter Total Fair Value (2) December 31, 2019 (Dollars in thousands) Loan level swaps Receive fixed, pay variable 299 $ 156,690 $ 125,203 $ 85,603 $ 165,599 $ 1,044,315 $ 1,577,410 $ 48,596 Pay fixed, receive variable 290 $ 156,690 $ 125,203 $ 85,603 $ 165,599 $ 1,044,315 $ 1,577,410 $ (48,591) Foreign exchange contracts Buys foreign currency, sells U.S. currency 40 $ 91,434 $ — $ — $ — $ — $ 91,434 $ (81) Buys U.S. currency, sells foreign currency 40 $ 91,434 $ — $ — $ — $ — $ 91,434 $ 123 (1) The Company may enter into one dealer swap agreement which offsets multiple commercial borrower swap agreements.
Fair value of derivative financial instruments as well as their classification on the balance sheet	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the balance sheet and the potential effect of netting arrangements on its financial position, at the dates indicated: Asset Derivatives (1) Liability Derivatives (2) Fair Value at Fair Value at Fair Value at Fair Value at September 30 December 31 September 30 December 31 (Dollars in thousands) Derivatives designated as hedges Interest rate derivatives $ 54,047 (3) $ 23,140 (3) $ 1,561 (4) $ 197 (4) Derivatives not designated as hedges Customer Related Positions Loan level derivatives 145,517 (3) 52,374 (3) 145,501 (4) 52,369 (4) Foreign exchange contracts 3,785 1,191 3,759 1,149 Risk participation agreements 745 — 269 — Mortgage Derivatives Interest rate lock commitments 6,587 1,680 — — Forward sale loan commitments 61 — — 12 Forward sale hedge commitments — — 523 196 Total derivatives not designated as hedges 156,695 55,245 150,052 53,726 Total 210,742 78,385 151,613 53,923 Netting Adjustments (5) 12 — 18,988 — Net Derivatives on the Balance Sheet 210,754 78,385 132,625 53,923 Financial instruments (6) 54,047 24,882 54,047 24,882 Cash collateral pledged (received) — — 73,094 25,493 Net Derivative Amounts $ 156,707 $ 53,503 $ 5,484 $ 3,548
Effect of derivative financial instruments included in OCI and current earnings	The table below presents the effect of the Company’s derivative financial instruments included in OCI and current earnings for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands) Derivatives designated as hedges Gain (loss) in OCI on derivatives (effective portion), net of tax $ (2,729) $ 3,030 $ 20,452 $ 14,905 Gain reclassified from OCI into interest income or interest expense (effective portion) $ 4,339 $ 352 $ 9,901 $ 1,170 Loss reclassified from OCI into noninterest expense (loss on termination) $ (684) $ — $ (684) $ — Interest expense $ — $ — $ — $ — Other expense — — — — Total $ — $ — $ — $ — Derivatives not designated as hedges Changes in fair value of customer related positions Other income $ 21 $ 10 $ 46 $ 37 Other expense (28) (2) (52) (13) Changes in fair value of mortgage derivatives Mortgage banking income 2,027 366 4,653 1,913 Total $ 2,020 $ 374 $ 4,647 $ 1,937

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Tax provision and applicable tax rates [Table Text Block]	The following table sets forth information regarding the Company’s tax provision and applicable tax rates for the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 2020 2019 2020 2019 (Dollars in thousands) Combined federal and state income tax provision $ 11,199 $ 17,036 $ 21,126 $ 38,565 Effective income tax rate 24.31 % 24.73 % 19.62 % 24.68 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	Assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows as of the dates indicated: Fair Value Measurements at Reporting Date Using Balance Quoted Prices Significant Significant September 30, 2020 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 2,612 $ 2,612 $ — $ — Equity securities 21,119 21,119 — — Securities available for sale U.S. government agency securities 24,273 — 24,273 — Agency mortgage-backed securities 230,620 — 230,620 — Agency collateralized mortgage obligations 102,077 — 102,077 — State, county, and municipal securities 1,145 — 1,145 — Single issuer trust preferred securities issued by banks and insurers 469 — 469 — Pooled trust preferred securities issued by banks and insurers 1,021 — — 1,021 Small business administration pooled securities 63,873 — 63,873 — Loans held for sale 54,713 — 54,713 — Derivative instruments 210,742 — 210,742 — Liabilities Derivative instruments 151,613 — 151,613 — Total recurring fair value measurements $ 561,051 $ 23,731 $ 536,299 $ 1,021 Nonrecurring fair value measurements Assets Individually assessed collateral dependent loans $ 56,660 $ — $ — $ 56,660 Total nonrecurring fair value measurements $ 56,660 $ — $ — $ 56,660 Fair Value Measurements at Reporting Date Using Balance Quoted Prices Significant Significant December 31, 2019 (Dollars in thousands) Recurring fair value measurements Assets Trading securities $ 2,179 $ 2,179 $ — $ — Equity securities 21,261 21,261 — — Securities available for sale U.S. government agency securities 33,115 — 33,115 — Agency mortgage-backed securities 247,000 — 247,000 — Agency collateralized mortgage obligations 88,511 — 88,511 — State, county, and municipal securities 1,396 — 1,396 — Single issuer trust preferred securities issued by banks and insurers 493 — 493 — Pooled trust preferred securities issued by banks and insurers 1,114 — — 1,114 Small business administration pooled securities 54,795 — 54,795 — Loans held for sale 33,307 — 33,307 — Derivative instruments 78,385 — 78,385 — Liabilities Derivative instruments 53,923 — 53,923 — Total recurring fair value measurements $ 507,633 $ 23,440 $ 483,079 $ 1,114 Nonrecurring fair value measurements: Assets Collateral dependent impaired loans $ 25,515 $ — $ — $ 25,515 Total nonrecurring fair value measurements $ 25,515 $ — $ — $ 25,515
Reconciliation for all assets and liabilities measured at fair value on a recurring basis	The table below presents a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3), which were valued using pricing models and discounted cash flow methodologies, for the periods indicated: Three Months Ended September 30 2020 2019 (Dollars in thousands) Pooled Trust Preferred Securities Beginning balance $ 986 $ 1,281 Gain and (losses) (realized/unrealized) Included in other comprehensive income 41 (14) Settlements (6) (161) Ending balance $ 1,021 $ 1,106 Nine Months Ended September 30 2020 2019 (Dollars in thousands) Pooled Trust Preferred Securities Beginning balance $ 1,114 $ 1,329 Losses (realized/unrealized) Included in other comprehensive income (38) (38) Settlements (55) (185) Ending balance $ 1,021 $ 1,106
Investments in securities that are classified as level 3	The following table sets forth certain unobservable inputs regarding the Company’s financial instruments that are classified as Level 3 as of the dates indicated: September 30 December 31 September 30 December 31 September 30 December 31 Valuation Technique Fair Value Unobservable Inputs Range Weighted Average (Dollars in thousands) Discounted cash flow methodology Pooled trust preferred securities $ 1,021 $ 1,114 Cumulative prepayment 0% - 56% 0% - 57% 2.6% 2.6% Cumulative default 4% - 100% 2% - 100% 11.9% 13.5% Loss given default 85% - 100% 85% - 100% 94.0% 93.6% Cure given default 0% - 75% 0% - 75% 60.9% 60.9% Appraisals of collateral(1) Individually assessed collateral dependent loans $ 56,660 n/a Collateral dependent impaired loans n/a $ 25,515 (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary.
The estimated fair values and related carrying amounts for assets and liabilities	The estimated fair values and related carrying amounts for assets and liabilities for which fair value is only disclosed are shown below as of the dates indicated: Fair Value Measurements at Reporting Date Using Carrying Fair Quoted Prices Significant Significant September 30, 2020 (Dollars in thousands) Financial assets Securities held to maturity(a) U.S. Treasury securities $ 4,021 $ 4,100 $ — $ 4,100 $ — Agency mortgage-backed securities 388,106 407,793 — 407,793 — Agency collateralized mortgage obligations 237,380 246,937 — 246,937 — Single issuer trust preferred securities issued by banks 1,500 1,498 — 1,498 — Small business administration pooled securities 28,566 30,139 — 30,139 — Loans, net of allowance for credit losses(b) 9,232,908 9,185,023 — — 9,185,023 Federal Home Loan Bank stock(c) 15,090 15,090 — 15,090 — Cash surrender value of life insurance policies(d) 199,453 199,453 — 199,453 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 9,792,667 $ 9,792,667 $ — $ 9,792,667 $ — Time certificates of deposits(f) 1,058,641 1,065,818 — 1,065,818 — Federal Home Loan Bank borrowings(f) 145,765 145,975 — 145,975 — Long-term borrowings(f) 37,447 36,448 — 36,448 — Junior subordinated debentures(g) 62,850 67,883 — 67,883 — Subordinated debentures(f) 49,672 47,173 — — 47,173 Fair Value Measurements at Reporting Date Using Carrying Fair Quoted Prices Significant Significant December 31, 2019 (Dollars in thousands) Financial assets Securities held to maturity(a) U.S. government agency securities $ 12,874 $ 12,997 $ — $ 12,997 $ — U.S. Treasury securities 4,032 4,053 $ — 4,053 — Agency mortgage-backed securities 397,414 405,802 — 405,802 — Agency collateralized mortgage obligations 293,662 297,314 — 297,314 — Single issuer trust preferred securities issued by banks 1,500 1,490 — 1,490 — Small business administration pooled securities 31,324 31,607 — 31,607 — Loans, net of allowance for credit losses(b) 8,780,384 8,613,635 — — 8,613,635 Federal Home Loan Bank stock(c) 14,424 14,424 — 14,424 — Cash surrender value of life insurance policies(d) 197,372 197,372 — 197,372 — Financial liabilities Deposit liabilities, other than time deposits(e) $ 7,752,052 $ 7,752,052 $ — $ 7,752,052 $ — Time certificates of deposits(f) 1,395,315 1,396,760 — 1,396,760 — Federal Home Loan Bank borrowings(f) 115,748 115,881 — 115,881 — Long-term borrowings (f) 74,906 72,219 — 72,219 — Junior subordinated debentures(g) 62,848 65,603 — 65,603 — Subordinated debentures(f) 49,601 52,870 — — 52,870 (a) The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis. (b) Fair value of loans is measured using the exit price valuation method, determined primarily by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows, while incorporating liquidity and credit assumptions. Additionally, this amount excludes individually assessed collateral dependent loans, which are deemed to be marked to fair value on a nonrecurring basis. (c) Federal Home Loan Bank stock has no quoted market value and is carried at cost; therefore the carrying amount approximates fair value. (d) Cash surrender value of life insurance policies is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore, carrying amount approximates fair value. (e) Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date. (f) Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities. (g) Fair value was determined based upon market prices of securities with similar terms and maturities.

Revenue Recognition Revenue (Ta

Revenue Recognition Revenue (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	The following table presents the revenue streams that the Company has disaggregated as of the periods indicated: Three Months Ended Nine Months Ended September 30 September 30 September 30 September 30 (Dollars in thousands) Deposit account fees (inclusive of cash management fees) $ 3,428 $ 5,299 $ 11,227 $ 14,785 Interchange fees 2,025 4,913 10,665 13,473 ATM fees 708 939 1,872 2,461 Investment management - wealth management and advisory services 6,997 6,635 20,113 19,127 Investment management - retail investments and insurance revenue 574 553 1,583 1,962 Merchant processing income 330 230 1,000 834 Credit card income 216 — 550 — Other noninterest income 905 1,487 2,651 4,068 Total noninterest income in-scope of ASC 606 15,183 20,056 49,661 56,710 Total noninterest income out-of-scope of ASC 606 14,164 11,760 34,311 25,287 Total noninterest income $ 29,347 $ 31,816 $ 83,972 $ 81,997
Contract with Customer, Asset and Liability [Table Text Block]	The following table provides the amount of investment management revenue earned but not received as of the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Receivables, included in other assets $ 4,383 $ 2,341

Comprehensive Income_Loss (Tabl

Comprehensive Income/Loss (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Comprehensive income	The following tables present a reconciliation of the changes in the components of other comprehensive income (loss) for the periods indicated, including the amount of income tax (expense) benefit allocated to each component of other comprehensive income (loss): Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (857) $ 148 $ (709) $ 13,598 $ (3,265) $ 10,333 Less: net security losses reclassified into other noninterest expense — — — — — — Net change in fair value of securities available for sale (857) 148 (709) 13,598 (3,265) 10,333 Change in fair value of cash flow hedges (143) 41 (102) 37,674 (10,597) 27,077 Less: net cash flow hedge gains reclassified into interest income or interest expense 4,339 (1,220) 3,119 9,901 (2,784) 7,117 Less: Loss on termination of hedge reclassified into noninterest expense (684) 192 (492) (684) 192 (492) Net change in fair value of cash flow hedges (3,798) 1,069 (2,729) 28,457 (8,005) 20,452 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (2) 1 (1) (1,392) 392 (1,000) Amortization of net actuarial losses 245 (69) 176 736 (207) 529 Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 312 (87) 225 (449) 127 (322) Total other comprehensive income (loss) $ (4,343) $ 1,130 $ (3,213) $ 41,606 $ (11,143) $ 30,463 Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ 2,858 $ (683) $ 2,175 $ 14,699 $ (3,401) $ 11,298 Less: net security losses reclassified into other noninterest expense — — — (1,462) 411 (1,051) Net change in fair value of securities available for sale 2,858 (683) 2,175 16,161 (3,812) 12,349 Change in fair value of cash flow hedges 4,568 (1,285) 3,283 21,913 (6,167) 15,746 Less: net cash flow hedge gains reclassified into interest income or interest expense 352 (99) 253 1,170 (329) 841 Net change in fair value of cash flow hedges 4,216 (1,186) 3,030 20,743 (5,838) 14,905 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (11) 3 (8) (33) 9 (24) Amortization of net actuarial gains (2) 1 (1) (6) 2 (4) Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 56 (15) 41 168 (47) 121 Total other comprehensive income $ 7,130 $ (1,884) $ 5,246 $ 37,072 $ (9,697) $ 27,375
Company's accumulated other comprehensive loss, net of tax	Information on the Company’s accumulated other comprehensive income (loss), net of tax, is comprised of the following components as of the dates indicated: Unrealized Gain (Loss) Unrealized Gain on Cash Flow Hedge Defined Benefit Postretirement Plans Accumulated Other Comprehensive Income (Loss) (Dollars in thousands) 2020 Beginning balance: January 1, 2020 $ 4,398 $ 16,479 $ (2,708) $ 18,169 Net change in other comprehensive income (loss) 10,333 20,452 (322) 30,463 Ending balance: September 30, 2020 $ 14,731 $ 36,931 $ (3,030) $ 48,632 2019 Beginning balance: January 1, 2019 $ (5,947) $ 6,148 $ (1,374) $ (1,173) Net change in other comprehensive income (loss) 12,349 14,905 121 27,375 Ending balance: September 30, 2019 $ 6,402 $ 21,053 $ (1,253) $ 26,202

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block]	The following table summarizes the above financial instruments at the dates indicated: September 30, 2020 December 31, 2019 (Dollars in thousands) Commitments to extend credit $ 3,258,341 $ 3,337,930 Standby letters of credit 20,902 21,565 Deferred standby letter of credit fees 191 158 Loan exposures with recourse 343,314 404,532

Securities Securities (Equity g

Securities Securities (Equity gains and losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity securities gains and losses [Abstract]
Equity Securities, FV-NI, Gain (Loss)	$ 308	$ 211	$ (107)	$ 1,562
Equity Securities, FV-NI, Realized Gain (Loss)	0	0	6	6
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 308	$ 211	$ (113)	$ 1,556

Securities (Reconciliation of f

Securities (Reconciliation of fair value of available for sale securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	$ 19,871	$ 6,118
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(552)	(397)
Debt Securities, Available-for-sale	423,478	426,424
Debt Securities, Available-for-sale, Amortized Cost	404,159	420,703
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	30,896	13,428
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(2)	(971)
Held to Maturity, Fair Value, Total	690,467	753,263
Amortized Cost	1,063,732
U.S. government agency securities
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,798	642
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	24,273	33,115
Debt Securities, Available-for-sale, Amortized Cost	22,475	32,473
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain		123
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held to Maturity, Fair Value, Total	0	12,997
U.S. Treasury securities
Reconciliation of fair value of securities
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	79	21
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held to Maturity, Fair Value, Total	4,100	4,053
Agency mortgage-backed securities
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	10,471	3,456
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(1)	(4)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	230,620	247,000
Debt Securities, Available-for-sale, Amortized Cost	220,150	243,548
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	19,687	8,445
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(57)
Held to Maturity, Fair Value, Total	407,793	405,802
Agency Collateralized Mortgage Obligations [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3,539	1,225
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(119)	(19)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	102,077	88,511
Debt Securities, Available-for-sale, Amortized Cost	98,657	87,305
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	9,557	4,501
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(849)
Held to Maturity, Fair Value, Total	246,937	297,314
US States and Political Subdivisions Debt Securities [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	20	19
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	1,145	1,396
Debt Securities, Available-for-sale, Amortized Cost	1,125	1,377
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		5
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(20)	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	469	493
Debt Securities, Available-for-sale, Amortized Cost	489	488
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(2)	(10)
Held to Maturity, Fair Value, Total	1,498	1,490
Pooled trust preferred securities issued by banks and insurers
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(412)	(374)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	1,021	1,114
Debt Securities, Available-for-sale, Amortized Cost	1,433	1,488
Small Business Administration Pooled Securities [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4,043	771
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale	63,873	54,795
Debt Securities, Available-for-sale, Amortized Cost	59,830	54,024
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	1,573	338
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(55)
Held to Maturity, Fair Value, Total	$ 30,139	$ 31,607

Securities Securities (Availabl

Securities Securities (Available for sale securities in continuous unrealized loss position) (Details) $ in Thousands	Sep. 30, 2020USD ($)holding
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 28,137
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(140)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,021
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	412
Debt Securities, Available-for-sale, Unrealized Loss Position	29,158
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 552
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 399
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	399
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 1
Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 27,269
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(119)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	27,269
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 119
Single issuer trust preferred securities issued by banks and insurers
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 469
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(20)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	469
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 20
Pooled trust preferred securities issued by banks and insurers
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,021
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	412
Debt Securities, Available-for-sale, Unrealized Loss Position	1,021
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 412

Securities Securities (Reconcil

Securities Securities (Reconciliation of amortized cost of held to maturity securities) (Details) $ in Thousands	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)holding
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	$ 659,573	$ 740,806
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	30,896	13,428
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(2)	(971)
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	690,467	753,263
Small Business Administration Pooled Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		7,349
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		55
Debt Securities, Held-to-maturity	28,566	31,324
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	1,573	338
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(55)
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	30,139	$ 31,607
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		1
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 7,349
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(55)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		0
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		0
Trust Preferred Securities Subject to Mandatory Redemption [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	1,500	1,500
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(2)	(10)
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	1,498	1,490
Collateralized Debt Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		85,858
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		868
Debt Securities, Held-to-maturity	237,380	293,662
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	9,557	4,501
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(849)
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	246,937	$ 297,314
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		17
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 48,476
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(215)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		37,382
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		653
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		34,252
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		61
Debt Securities, Held-to-maturity	388,106	397,414
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	19,687	8,445
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(57)
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	407,793	$ 405,802
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		12
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 34,009
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(59)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		243
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		2
US Treasury Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	4,021	4,032
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	79	21
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	4,100	4,053
U.S. government agency securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	0	12,874
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain		123
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Fair Value	$ 0	12,997
Equity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		130,063
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ 1,368
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		32
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 89,834
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(329)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		40,229
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		$ 1,039

Securities (Schedule of Contrac

Securities (Schedule of Contractual Maturities of Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Available for Sale, Fair Value
Debt Securities, Available-for-sale, Amortized Cost	$ 404,159	$ 420,703
Debt Securities, Available-for-sale	423,478	426,424
Held to Maturity, Fair Value
Debt Securities, Held-to-maturity	659,573	740,806
Held to Maturity, Fair Value, Total	690,467	753,263
Available for Sale Securities and Held to Maturity Securities Amortized Cost	1,063,732
Debt Securities, Available-for-sale and Held-to-maturity	1,113,945
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	10,026
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	10,109
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	86,523
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	89,073
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	106,650
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	113,935
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Ten Years, Amortized Cost	860,533
Debt Securities, Available-for-sale and Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Ten Years, Fair Value	900,828
U.S. government agency securities
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	10,001
Available for Sale, Amortized Cost, Due after five to ten years	12,474
Available for Sale, Amortized Cost, Due after ten years	0
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	10,288
Available for Sale, Fair Value, Due after five to ten years	13,985
Available for Sale, Fair Value, Due after ten years	0
Debt Securities, Available-for-sale, Amortized Cost	22,475	32,473
Debt Securities, Available-for-sale	24,273	33,115
Held to Maturity, Fair Value
Debt Securities, Held-to-maturity	0	12,874
Held to Maturity, Fair Value, Total	0	12,997
Small Business Administration Pooled Securities [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	59,830
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	63,873
Debt Securities, Available-for-sale, Amortized Cost	59,830	54,024
Debt Securities, Available-for-sale	63,873	54,795
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	0
Held to Maturity, Amortized Cost, Due after five to ten years	0
Held to Maturity, Amortized Cost, Due after ten years	28,566
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	0
Held to Maturity, Fair Value, Due after five to ten years	0
Held to Maturity, Fair Value, Due after ten years	30,139
Debt Securities, Held-to-maturity	28,566	31,324
Held to Maturity, Fair Value, Total	30,139	31,607
Debt Securities [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	515
Available for Sale, Amortized Cost, Due after one year to five years	82,045
Available for Sale, Amortized Cost, Due after five to ten years	51,620
Available for Sale, Amortized Cost, Due after ten years	269,979
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	516
Available for Sale, Fair Value, Due after one year to five years	84,483
Available for Sale, Fair Value, Due after five to ten years	56,148
Available for Sale, Fair Value, Due after ten years	282,331
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	9,511
Held to Maturity, Amortized Cost, Due after one year to five years	4,478
Held to Maturity, Amortized Cost, Due after five to ten years	55,030
Held to Maturity, Amortized Cost, Due after ten years	590,554
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	9,593
Held to Maturity, Fair Value, Due after one year to five years	4,590
Held to Maturity, Fair Value, Due after five to ten years	57,787
Held to Maturity, Fair Value, Due after ten years	618,497
Held to Maturity, Fair Value, Total	690,467
Pooled trust preferred securities issued by banks and insurers
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	1,433
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	1,021
Debt Securities, Available-for-sale, Amortized Cost	1,433	1,488
Debt Securities, Available-for-sale	1,021	1,114
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	489
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	469
Debt Securities, Available-for-sale, Amortized Cost	489	488
Debt Securities, Available-for-sale	469	493
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	0
Held to Maturity, Amortized Cost, Due after five to ten years	1,500
Held to Maturity, Amortized Cost, Due after ten years	0
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	0
Held to Maturity, Fair Value, Due after five to ten years	1,498
Held to Maturity, Fair Value, Due after ten years	0
Debt Securities, Held-to-maturity	1,500	1,500
Held to Maturity, Fair Value, Total	1,498	1,490
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	515
Available for Sale, Amortized Cost, Due after one year to five years	420
Available for Sale, Amortized Cost, Due after five to ten years	190
Available for Sale, Amortized Cost, Due after ten years	0
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	516
Available for Sale, Fair Value, Due after one year to five years	422
Available for Sale, Fair Value, Due after five to ten years	207
Available for Sale, Fair Value, Due after ten years	0
Debt Securities, Available-for-sale, Amortized Cost	1,125	1,377
Debt Securities, Available-for-sale	1,145	1,396
Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	0
Available for Sale, Amortized Cost, Due after five to ten years	0
Available for Sale, Amortized Cost, Due after ten years	98,657
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	0
Available for Sale, Fair Value, Due after five to ten years	0
Available for Sale, Fair Value, Due after ten years	102,077
Debt Securities, Available-for-sale, Amortized Cost	98,657	87,305
Debt Securities, Available-for-sale	102,077	88,511
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	0
Held to Maturity, Amortized Cost, Due after one year to five years	0
Held to Maturity, Amortized Cost, Due after five to ten years	0
Held to Maturity, Amortized Cost, Due after ten years	237,380
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	0
Held to Maturity, Fair Value, Due after one year to five years	0
Held to Maturity, Fair Value, Due after five to ten years	0
Held to Maturity, Fair Value, Due after ten years	246,937
Debt Securities, Held-to-maturity	237,380	293,662
Held to Maturity, Fair Value, Total	246,937	297,314
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available for Sale, Amortized Cost, Due in one year or less	0
Available for Sale, Amortized Cost, Due after one year to five years	71,624
Available for Sale, Amortized Cost, Due after five to ten years	38,956
Available for Sale, Amortized Cost, Due after ten years	109,570
Available for Sale, Fair Value
Available for Sale, Fair Value, Due in one year or less	0
Available for Sale, Fair Value, Due after one year to five years	73,773
Available for Sale, Fair Value, Due after five to ten years	41,956
Available for Sale, Fair Value, Due after ten years	114,891
Debt Securities, Available-for-sale, Amortized Cost	220,150	243,548
Debt Securities, Available-for-sale	230,620	247,000
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	8,510
Held to Maturity, Amortized Cost, Due after one year to five years	1,458
Held to Maturity, Amortized Cost, Due after five to ten years	53,530
Held to Maturity, Amortized Cost, Due after ten years	324,608
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	8,574
Held to Maturity, Fair Value, Due after one year to five years	1,509
Held to Maturity, Fair Value, Due after five to ten years	56,289
Held to Maturity, Fair Value, Due after ten years	341,421
Debt Securities, Held-to-maturity	388,106	397,414
Held to Maturity, Fair Value, Total	407,793	405,802
US Treasury Securities [Member]
Held to Maturity, Amortized Cost
Held to Maturity, Amortized Cost, Due in one year or less	1,001
Held to Maturity, Amortized Cost, Due after one year to five years	3,020
Held to Maturity, Amortized Cost, Due after five to ten years	0
Held to Maturity, Amortized Cost, Due after ten years	0
Held to Maturity, Fair Value
Held to Maturity, Fair Value, Due in one year or less	1,019
Held to Maturity, Fair Value, Due after one year to five years	3,081
Held to Maturity, Fair Value, Due after five to ten years	0
Held to Maturity, Fair Value, Due after ten years	0
Debt Securities, Held-to-maturity	4,021	4,032
Held to Maturity, Fair Value, Total	$ 4,100	$ 4,053

Securities (Unrealized Loss NOT

Securities (Unrealized Loss NOT deemed to be OTTI) (Details) $ in Thousands	Sep. 30, 2020USD ($)holding	Dec. 31, 2019USD ($)holding
Gain (Loss) on Securities [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 29,158
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,021
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(412)
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (552)
Summary of gross unrealized losses and fair value of investments
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 28,137
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(140)
Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		12
Debt Securities, Available-for-sale, Unrealized Loss Position	399
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (1)
Summary of gross unrealized losses and fair value of investments
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 399
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 34,009
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(59)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		243
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		(2)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		34,252
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ (61)
Agency Collateralized Mortgage Obligations [Member]
Gain (Loss) on Securities [Line Items]
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		17
Debt Securities, Available-for-sale, Unrealized Loss Position	27,269
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (119)
Summary of gross unrealized losses and fair value of investments
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 27,269
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(119)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 48,476
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(215)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		37,382
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		(653)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		85,858
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ (868)
Single issuer trust preferred securities issued by banks and insurers
Gain (Loss) on Securities [Line Items]
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		1
Debt Securities, Available-for-sale, Unrealized Loss Position	469
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (20)
Summary of gross unrealized losses and fair value of investments
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 469
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(20)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 0
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		0
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		1,490
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		(10)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		1,490
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ (10)
Pooled trust preferred securities issued by banks and insurers
Gain (Loss) on Securities [Line Items]
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		1
Debt Securities, Available-for-sale, Unrealized Loss Position	1,021
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,021
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(412)
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (412)
Summary of gross unrealized losses and fair value of investments
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 0
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		0
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		1,114
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		(374)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		1,114
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ (374)
Small Business Administration Pooled Securities [Member]
Gain (Loss) on Securities [Line Items]
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		1
Summary of gross unrealized losses and fair value of investments
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 7,349
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(55)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		0
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		0
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		7,349
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ (55)
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Available for Sale and Held to Maturity Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions | holding		32
Summary of gross unrealized losses and fair value of investments
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Less than Twelve Months Fair Value		$ 89,834
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months		(329)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Twelve Months or Longer Fair Value		40,229
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months		(1,039)
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Fair Value		130,063
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss		$ (1,368)

Securities (Details Textual) (D

Securities (Details Textual) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	$ 36,700		$ 36,700
Trading	2,612		2,612		$ 2,179
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)		$ 0		$ 0
Debt Securities, Available-for-sale	423,478		423,478		426,424
Debt Securities, Available-for-Sale, Accrued Interest Writeoff	0		0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)	0		0
Debt Securities, Available-for-sale, Realized Gain (Loss)	0	0	0	(1,500)
Debt Securities, Available-for-sale, Past due	0		0
Debt Securities, Available-for-sale, Nonaccrual	0		0
Debt Securities, Held-to-maturity, Past Due	0		0
Debt Securities, Held-to-maturity, Nonaccrual	0		0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held					0
Securities (Textual) [Abstract]
Callable Securities in Investment Portfolio	3,900		3,900
Pledged Financial Instruments, Not Separately Reported, Securities	417,100		417,100		375,500
Investments in obligations of individual states, counties or municipalities which exceed 10% of equity	0		0		0
Debt Securities, Held-to-maturity	659,573		659,573		740,806
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)	0		0
Debt Securities, Available-for-Sale, Accrued Interest Writeoff	0		0
Debt Securities, Available-for-sale, Realized Gain (Loss)	0	0	0	1,500
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Period Increase (Decrease)	0		0
Debt Securities, Held-to-Maturity, Accrued Interest, Writeoff	0		0
Debt Securities, Held-to-maturity, Sold, Realized Gain (Loss)	0	$ 0	0	$ 0
Equity Securities, FV-NI	21,119		21,119		$ 21,261
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	1,400		1,400
Held-to-maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest Receivable	$ 1,700		$ 1,700

Loans, Allowance for Credit L_3

Loans, Allowance for Credit Losses and Credit Quality Financing Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 115,625	$ 115,625	$ 112,176	$ 67,740
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(1,137)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		1,157
Allowance for Loan and Lease Losses, Write-offs	(4,304)	(5,748)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	253	1,113
Provision for Loan and Lease Losses	7,500	52,500
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	28,219	28,219	25,662	17,594
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(1,984)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		49
Allowance for Loan and Lease Losses, Write-offs	(185)	(185)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1	47
Provision for Loan and Lease Losses	2,741	12,698
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	39,386	39,386	36,956	32,935
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(13,048)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		337
Allowance for Loan and Lease Losses, Write-offs	(3,885)	(3,885)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	9	9
Provision for Loan and Lease Losses	6,306	23,038
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	5,210	5,210	4,501	6,053
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		(3,652)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		0
Allowance for Loan and Lease Losses, Write-offs	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	0	0
Provision for Loan and Lease Losses	709	2,809
Small Business [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	4,593	4,593	4,561	1,746
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		495
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		0
Allowance for Loan and Lease Losses, Write-offs	(49)	(194)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	2	8
Provision for Loan and Lease Losses	79	2,538
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	14,163	14,163	15,046	3,440
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		9,828
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		423
Allowance for Loan and Lease Losses, Write-offs	0	0
Allowance for Loan and Lease Loss, Recovery of Bad Debts	1	2
Provision for Loan and Lease Losses	(884)	470
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	23,572	23,572	24,860	5,576
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		7,012
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		319
Allowance for Loan and Lease Losses, Write-offs	0	(142)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	21	174
Provision for Loan and Lease Losses	(1,309)	10,633
Consumer - Other [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	482	482	$ 590	$ 396
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method		212
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase		29
Allowance for Loan and Lease Losses, Write-offs	(185)	(1,342)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	219	873
Provision for Loan and Lease Losses	$ (142)	$ 314

Loans, Allowance for Credit L_4

Loans, Allowance for Credit Losses and Credit Quality Finance Receivable Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	$ 1,504,307
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,047,533
Financing Receivable, Originated Three Years before Latest Fiscal Year	970,908
Financing Receivable, Originated Four Years before Latest Fiscal Year	758,331
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,445,238
Financing Receivable, Revolving	1,454,822
Financing Receivable, after Allowance for Credit Loss	2,199,885
Loans and Leases Receivable, Gross	9,405,193	$ 8,873,639
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	877,770
Financing Receivable, Originated Two Years before Latest Fiscal Year	561,699
Financing Receivable, Originated Three Years before Latest Fiscal Year	616,367
Financing Receivable, Originated Four Years before Latest Fiscal Year	428,865
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	806,109
Financing Receivable, Revolving	39,998
Financing Receivable, after Allowance for Credit Loss	778,315
Loans and Leases Receivable, Gross	4,125,464	4,002,359
Commercial Real Estate [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	15,957
Financing Receivable, Originated Two Years before Latest Fiscal Year	20,313
Financing Receivable, Originated Three Years before Latest Fiscal Year	7,941
Financing Receivable, Originated Four Years before Latest Fiscal Year	27,253
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	47,875
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	20,639
Loans and Leases Receivable, Gross	139,978
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	859,548
Financing Receivable, Originated Two Years before Latest Fiscal Year	512,371
Financing Receivable, Originated Three Years before Latest Fiscal Year	587,345
Financing Receivable, Originated Four Years before Latest Fiscal Year	399,442
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	751,629
Financing Receivable, Revolving	39,998
Financing Receivable, after Allowance for Credit Loss	753,415
Loans and Leases Receivable, Gross	3,920,089
Commercial Real Estate [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,265
Financing Receivable, Originated Two Years before Latest Fiscal Year	10,092
Financing Receivable, Originated Three Years before Latest Fiscal Year	21,081
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,170
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	6,605
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	4,261
Loans and Leases Receivable, Gross	46,474
Commercial Real Estate [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	18,923
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	18,923
Commercial Real Estate [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	0
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	156,992
Financing Receivable, Originated Two Years before Latest Fiscal Year	137,899
Financing Receivable, Originated Three Years before Latest Fiscal Year	44,899
Financing Receivable, Originated Four Years before Latest Fiscal Year	26,767
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	24,214
Financing Receivable, Revolving	650,681
Financing Receivable, after Allowance for Credit Loss	1,018,266
Loans and Leases Receivable, Gross	2,062,345	1,395,036
Commercial And Industrial [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,302
Financing Receivable, Originated Two Years before Latest Fiscal Year	7,833
Financing Receivable, Originated Three Years before Latest Fiscal Year	4,573
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,219
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	318
Financing Receivable, Revolving	15,248
Financing Receivable, after Allowance for Credit Loss	2,560
Loans and Leases Receivable, Gross	34,103
Commercial And Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	153,137
Financing Receivable, Originated Two Years before Latest Fiscal Year	107,318
Financing Receivable, Originated Three Years before Latest Fiscal Year	34,826
Financing Receivable, Originated Four Years before Latest Fiscal Year	23,065
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	22,334
Financing Receivable, Revolving	601,937
Financing Receivable, after Allowance for Credit Loss	1,012,974
Loans and Leases Receivable, Gross	1,958,168
Commercial And Industrial [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,553
Financing Receivable, Originated Two Years before Latest Fiscal Year	22,748
Financing Receivable, Originated Three Years before Latest Fiscal Year	5,500
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,483
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,419
Financing Receivable, Revolving	33,496
Financing Receivable, after Allowance for Credit Loss	2,732
Loans and Leases Receivable, Gross	69,931
Commercial And Industrial [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	143
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	143
Commercial And Industrial [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	205,772
Financing Receivable, Originated Two Years before Latest Fiscal Year	79,338
Financing Receivable, Originated Three Years before Latest Fiscal Year	66,406
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	6,750
Financing Receivable, Revolving	31,700
Financing Receivable, after Allowance for Credit Loss	182,291
Loans and Leases Receivable, Gross	573,334	547,293
Construction Loans [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	9,352
Financing Receivable, Originated Two Years before Latest Fiscal Year	5,037
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	328
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	14,717
Construction Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	196,420
Financing Receivable, Originated Two Years before Latest Fiscal Year	73,298
Financing Receivable, Originated Three Years before Latest Fiscal Year	66,406
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	6,750
Financing Receivable, Revolving	31,372
Financing Receivable, after Allowance for Credit Loss	182,291
Loans and Leases Receivable, Gross	557,614
Construction Loans [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,003
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	1,003
Construction Loans [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	0
Construction Loans [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	0
Small Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	29,184
Financing Receivable, Originated Two Years before Latest Fiscal Year	20,900
Financing Receivable, Originated Three Years before Latest Fiscal Year	14,807
Financing Receivable, Originated Four Years before Latest Fiscal Year	15,381
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	23,599
Financing Receivable, Revolving	36,120
Financing Receivable, after Allowance for Credit Loss	27,641
Loans and Leases Receivable, Gross	167,632	174,497
Small Business [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	10
Financing Receivable, Originated Two Years before Latest Fiscal Year	16
Financing Receivable, Originated Three Years before Latest Fiscal Year	10
Financing Receivable, Originated Four Years before Latest Fiscal Year	755
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	232
Financing Receivable, Revolving	736
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	1,759
Small Business [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	28,766
Financing Receivable, Originated Two Years before Latest Fiscal Year	20,806
Financing Receivable, Originated Three Years before Latest Fiscal Year	14,627
Financing Receivable, Originated Four Years before Latest Fiscal Year	14,528
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	22,644
Financing Receivable, Revolving	34,569
Financing Receivable, after Allowance for Credit Loss	27,457
Loans and Leases Receivable, Gross	163,397
Small Business [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	408
Financing Receivable, Originated Two Years before Latest Fiscal Year	78
Financing Receivable, Originated Three Years before Latest Fiscal Year	170
Financing Receivable, Originated Four Years before Latest Fiscal Year	98
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	723
Financing Receivable, Revolving	786
Financing Receivable, after Allowance for Credit Loss	184
Loans and Leases Receivable, Gross	2,447
Small Business [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	29
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	29
Small Business [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	0
Residential Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	167,901
Financing Receivable, Originated Two Years before Latest Fiscal Year	187,954
Financing Receivable, Originated Three Years before Latest Fiscal Year	168,283
Financing Receivable, Originated Four Years before Latest Fiscal Year	241,805
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	453,943
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	132,419
Loans and Leases Receivable, Gross	1,352,305	$ 1,590,569
Residential Real Estate [Member] | Default [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	760
Financing Receivable, Originated Three Years before Latest Fiscal Year	235
Financing Receivable, Originated Four Years before Latest Fiscal Year	167
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	4,724
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	728
Loans and Leases Receivable, Gross	6,614
Residential Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	167,901
Financing Receivable, Originated Two Years before Latest Fiscal Year	187,194
Financing Receivable, Originated Three Years before Latest Fiscal Year	168,048
Financing Receivable, Originated Four Years before Latest Fiscal Year	241,638
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	449,219
Financing Receivable, Revolving	0
Financing Receivable, after Allowance for Credit Loss	131,691
Loans and Leases Receivable, Gross	1,345,691
Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	66,238
Financing Receivable, Originated Two Years before Latest Fiscal Year	59,534
Financing Receivable, Originated Three Years before Latest Fiscal Year	59,387
Financing Receivable, Originated Four Years before Latest Fiscal Year	44,817
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	122,852
Financing Receivable, Revolving	683,828
Financing Receivable, after Allowance for Credit Loss	60,274
Loans and Leases Receivable, Gross	1,101,054
Home Equity Loan [Member] | Default [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	455
Financing Receivable, Revolving	2,044
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	2,566
Home Equity Loan [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	66,238
Financing Receivable, Originated Two Years before Latest Fiscal Year	59,534
Financing Receivable, Originated Three Years before Latest Fiscal Year	59,387
Financing Receivable, Originated Four Years before Latest Fiscal Year	44,817
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	122,397
Financing Receivable, Revolving	681,784
Financing Receivable, after Allowance for Credit Loss	60,274
Loans and Leases Receivable, Gross	1,098,488
Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	450
Financing Receivable, Originated Two Years before Latest Fiscal Year	209
Financing Receivable, Originated Three Years before Latest Fiscal Year	759
Financing Receivable, Originated Four Years before Latest Fiscal Year	696
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	7,771
Financing Receivable, Revolving	12,495
Financing Receivable, after Allowance for Credit Loss	679
Loans and Leases Receivable, Gross	23,059
Consumer Loan [Member] | Default [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	20
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	34
Financing Receivable, Revolving	2
Financing Receivable, after Allowance for Credit Loss	0
Loans and Leases Receivable, Gross	56
Consumer Loan [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	450
Financing Receivable, Originated Two Years before Latest Fiscal Year	209
Financing Receivable, Originated Three Years before Latest Fiscal Year	739
Financing Receivable, Originated Four Years before Latest Fiscal Year	696
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	7,737
Financing Receivable, Revolving	12,493
Financing Receivable, after Allowance for Credit Loss	679
Loans and Leases Receivable, Gross	23,003
Revolving converted to term [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	24,169
Revolving converted to term [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	16,341
Revolving converted to term [Member] | Commercial Real Estate [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	16,341
Revolving converted to term [Member] | Commercial Real Estate [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Commercial Real Estate [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Commercial Real Estate [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	2,627
Revolving converted to term [Member] | Commercial And Industrial [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	50
Revolving converted to term [Member] | Commercial And Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	2,577
Revolving converted to term [Member] | Commercial And Industrial [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Commercial And Industrial [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Commercial And Industrial [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Construction Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,077
Revolving converted to term [Member] | Construction Loans [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Construction Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,077
Revolving converted to term [Member] | Construction Loans [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Construction Loans [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Construction Loans [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Small Business [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Small Business [Member] | Potential Weakness [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Small Business [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Small Business [Member] | Definite Weakness Loss Unlikely [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Small Business [Member] | Partial Loss Probable [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Small Business [Member] | Definite Loss [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Residential Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Residential Real Estate [Member] | Default [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Residential Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	4,124
Revolving converted to term [Member] | Home Equity Loan [Member] | Default [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	67
Revolving converted to term [Member] | Home Equity Loan [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	4,057
Revolving converted to term [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Consumer Loan [Member] | Default [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Revolving converted to term [Member] | Consumer Loan [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	$ 0

Loans, Allowance for Credit L_5

Loans, Allowance for Credit Losses and Credit Quality FICO and LTV (Details) - score		Sep. 30, 2020	Dec. 31, 2019
Residential Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable With Quality Of Loan Based On Weighted Average Fico Rating	[1]	749	749
Financing Receivable With Credit Quality Of Loan Based Upon the Weighted Average Loan-To-Value Ratio	[2]	57.70%	59.00%
Home Equity Line of Credit [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable With Quality Of Loan Based On Weighted Average Fico Rating	[1]	770	767
Financing Receivable With Credit Quality Of Loan Based Upon the Weighted Average Loan-To-Value Ratio	[2],[3]	46.60%	46.60%
[1]	The average FICO scores at September 30, 2020 are based upon rescores available from August 2020 and origination score data for loans booked in September 2020.  The average FICO scores at December 31, 2019 were based upon rescores available from November 2019 and origination score data for loans booked in December 2019.
[2]	The combined LTV ratios for September 30, 2020 are based upon updated automated valuations as of August 2020, when available, and/or the most current valuation data available.  The combined LTV ratios for December 31, 2019 were based upon updated automated valuations as of November 2019, when available, and/or the most current valuation data available as of such date.  The updated automated valuations provide new information on loans that may be available since the previous valuation was obtained.  If no new information is available, the valuation will default to the previously obtained data or most recent appraisal.
[3]	For home equity loans and lines in a subordinate lien, the LTV data represents a combined LTV, taking into account the senior lien data for loans and lines.

Loans, Allowance for Credit L_6

Loans, Allowance for Credit Losses and Credit Quality Finance Receivable, Nonaccrual (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		$ 55,369
Financing Receivable, Nonaccrual, No Allowance		42,655
Tdrs Recorded Investment On Nonaccrual Status		23,810	$ 24,766
Financing Receivable, Nonaccrual	[1]	98,024	45,892
Commercial And Industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		17,816
Financing Receivable, Nonaccrual, No Allowance		19,035
Financing Receivable, Nonaccrual		36,851	22,574
Commercial Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		17,501
Financing Receivable, Nonaccrual, No Allowance		20,663
Financing Receivable, Nonaccrual		38,164	3,016
Small Business [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		542
Financing Receivable, Nonaccrual		542	311
Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		13,379
Financing Receivable, Nonaccrual, No Allowance		2,850
Financing Receivable, Nonaccrual		16,229	13,360
Home Equity Line of Credit [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		6,052
Financing Receivable, Nonaccrual, No Allowance		107
Financing Receivable, Nonaccrual		6,159	6,570
Consumer - Other [Member]
Financing Receivable, Nonaccrual [Line Items]
Finance Receivable, Nonaccrual, with allowance		79
Financing Receivable, Nonaccrual		$ 79	$ 61
[1]	Included in these amounts were $23.8 million and $24.8 million of nonaccruing TDRs at September 30, 2020 and December 31, 2019, respectively.

Loans, Allowance for Credit L_7

Loans, Allowance for Credit Losses and Credit Quality Foreclosed Residential Real Estate Property (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosed residential real estate property held by the creditor	$ 0	$ 0
Mortgage Loans in Process of Foreclosure, Amount	$ 2,113	$ 3,294

Loans, Allowance for Credit L_8

Loans, Allowance for Credit Losses and Credit Quality Financing Receivable Past Due (Details) $ in Thousands	Sep. 30, 2020USD ($)loan	Dec. 31, 2019USD ($)loan
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	274	447
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 1	$ 2,157
Financing Receivable, Past Due	29,589	25,485
Financing Receivable, Not Past Due	9,375,604	8,848,154
Loans and Leases Receivable, Gross	$ 9,405,193	$ 8,873,639
Number Of Financing Receivables Total Past Due | loan	411	603
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	30	43
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	107	113
Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	1	1
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 0
Financing Receivable, Past Due	4,590	1,336
Financing Receivable, Not Past Due	2,057,755	1,393,700
Loans and Leases Receivable, Gross	$ 2,062,345	$ 1,395,036
Number Of Financing Receivables Total Past Due | loan	12	8
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	6	2
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	5	5
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	1	7
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 218	[1]
Financing Receivable, Past Due	9,723	3,922
Financing Receivable, Not Past Due	4,115,741	3,998,437
Loans and Leases Receivable, Gross	$ 4,125,464	$ 4,002,359
Number Of Financing Receivables Total Past Due | loan	8	16
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	2	1
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	5	8
Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	0	1
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 0
Financing Receivable, Past Due	0	560
Financing Receivable, Not Past Due	573,334	546,733
Loans and Leases Receivable, Gross	$ 573,334	$ 547,293
Number Of Financing Receivables Total Past Due | loan	0	1
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	0	0
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	0	0
Small Business [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	6	11
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 0
Financing Receivable, Past Due	1,093	967
Financing Receivable, Not Past Due	166,539	173,530
Loans and Leases Receivable, Gross	$ 167,632	$ 174,497
Number Of Financing Receivables Total Past Due | loan	22	20
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	4	3
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	12	6
Residential Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	11	17
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 1,652	[1]
Financing Receivable, Past Due	9,293	12,312
Financing Receivable, Not Past Due	1,343,012	1,578,257
Loans and Leases Receivable, Gross	$ 1,352,305	$ 1,590,569
Number Of Financing Receivables Total Past Due | loan	55	72
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	7	17
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	37	38
Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	18	23
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 265	[1]
Financing Receivable, Past Due	4,615	6,067
Financing Receivable, Not Past Due	1,096,439	1,127,731
Loans and Leases Receivable, Gross	$ 1,101,054	$ 1,133,798
Number Of Financing Receivables Total Past Due | loan	62	71
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	8	8
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	36	40
Consumer - Other [Member]
Financing Receivable, Past Due [Line Items]
Number Of Financing Receivables Thirty To Fifty Nine Days Past Due | loan	237	387	[2]
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 1	$ 22	[2]
Financing Receivable, Past Due	275	321	[2]
Financing Receivable, Not Past Due	22,784	29,766	[2]
Loans and Leases Receivable, Gross	$ 23,059	$ 30,087	[2]
Number Of Financing Receivables Total Past Due | loan	252	415	[2]
Number of Financing Receivables Sixty to Eighty Nine Days Past Due | loan	3	12	[2]
Number Of Financing Receivables Equal To Greater Than Ninety Days | loan	12	16	[2]
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 14,432	$ 4,155
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	3,608	323
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	8,269	194
Financial Asset, 60 to 89 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Small Business [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	455	15
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,631	3,055
Financial Asset, 60 to 89 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	468	524
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer - Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1	44	[2]
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	10,902	13,819
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	930	760
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,355	2,038
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Small Business [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	124	115
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	5,870	7,020
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	2,566	3,854
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer - Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	57	32	[2]
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4,255	7,511
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	52	253
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	99	1,690
Financial Asset, 30 to 59 Days Past Due [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	560
Financial Asset, 30 to 59 Days Past Due [Member] | Small Business [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	514	837
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,792	2,237
Financial Asset, 30 to 59 Days Past Due [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,581	1,689
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer - Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 217	$ 245	[2]
[1]	Represents purchased credit impaired ("PCI") loans that were accruing interest due to expectations of future cash collections.
[2]	Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances.

Loans, Allowance for Credit L_9

Loans, Allowance for Credit Losses and Credit Quality Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract	Dec. 31, 2019USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	5	5	17	9
Tdrs Recorded Investment On Accrual Status	$ 17,521		$ 17,521		$ 19,599
Tdrs Recorded Investment On Nonaccrual Status	23,810		23,810		24,766
Financing Receivable Recorded Investment Trouble Debt Restructuring	41,331		41,331		44,365
Amount Of Specific Reserves Included In Allowance For Loan Losses Associated With Trouble Debt Restructuring					855
Additional Commitments To Lend To Borrower For Trouble Debt Restructuring	158		158		$ 63
Financing Receivable, Troubled Debt Restructuring, Premodification	827	$ 448	3,580	$ 784
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 827	$ 453	$ 3,639	$ 789
Commercial And Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	2	1	5	2
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 83	$ 87	$ 391	$ 184
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 83	$ 87	$ 391	$ 184
Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	3	1	8	2
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 744	$ 133	$ 2,518	$ 283
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 744	$ 133	$ 2,518	$ 283
Small Business [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	0	1	2	2
Financing Receivable, Troubled Debt Restructuring, Premodification		$ 19	$ 112	$ 33
Financing Receivable, Troubled Debt Restructuring, Postmodification		19	$ 88	$ 33
Residential Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	0		2	1
Financing Receivable, Troubled Debt Restructuring, Premodification		163	$ 559	$ 163
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 168	$ 642	$ 168
Home Equity Line of Credit [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		1		2
Financing Receivable, Troubled Debt Restructuring, Premodification		$ 46		$ 121
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 46		$ 121

Loans, Allowance for Credit _10

Loans, Allowance for Credit Losses and Credit Quality Schedule of Debtor Troubled Debt Restructurings, Subsequent Period (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 0	$ 0	$ 0	$ 0
Financing Receivable, Modifications, Number of Contracts | contract	5	5	17	9
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 827,000	$ 448,000	$ 3,580,000	$ 784,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 827,000	$ 453,000	$ 3,639,000	$ 789,000
Commercial And Industrial [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	2	1	5	2
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 83,000	$ 87,000	$ 391,000	$ 184,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 83,000	$ 87,000	$ 391,000	$ 184,000
Commercial Real Estate [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	3	1	8	2
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 744,000	$ 133,000	$ 2,518,000	$ 283,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 744,000	$ 133,000	$ 2,518,000	$ 283,000
Small Business [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	0	1	2	2
Financing Receivable, Troubled Debt Restructuring, Premodification		$ 19,000	$ 112,000	$ 33,000
Financing Receivable, Troubled Debt Restructuring, Postmodification		19,000	$ 88,000	$ 33,000
Residential Real Estate [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract	0		2	1
Financing Receivable, Troubled Debt Restructuring, Premodification		163,000	$ 559,000	$ 163,000
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 168,000	$ 642,000	$ 168,000
Home Equity Line of Credit [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		1		2
Financing Receivable, Troubled Debt Restructuring, Premodification		$ 46,000		$ 121,000
Financing Receivable, Troubled Debt Restructuring, Postmodification		$ 46,000		$ 121,000
Residential Mortgage [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		1

Loans, Allowance for Credit _11

Loans, Allowance for Credit Losses and Credit Quality TDR on Financing Receivables Post Modification (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 827,000	$ 453,000	$ 3,639,000	$ 789,000
Financing Receivable, Troubled Debt Restructuring, Increase (Decrease) from Modification				831,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	0	0	0	0
Contractual Interest Rate Reduction [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification	218,000	0	822,000	150,000
Court ordered concession
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification	0	0	25,000	75,000
Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 609,000	$ 453,000	$ 2,792,000	$ 606,000

Loans, Allowance for Credit _12

Loans, Allowance for Credit Losses and Credit Quality Textual (Details) - USD ($)	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Days To Be Termed As Non Accrual Loans					90 days
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease) by percentage	3.10%				70.60%
Provision for credit losses	$ 7,500,000	$ 20,000,000	$ 25,000,000	$ 0	$ 52,500,000	$ 2,000,000
Loans with active Deferrals	583,800,000				583,800,000
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method					(1,137,000)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase					1,157,000
Interest Receivable	36,700,000				36,700,000
Loans and Leases Receivable, Allowance	(115,625,000)			(66,942,000)	(115,625,000)	(66,942,000)	$ (67,740,000)	$ (65,960,000)	$ (64,293,000)
Off-Balance Sheet, Credit Loss, Liability	1,000,000				1,000,000
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(3,400,000)				(47,900,000)
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	0			0	0	0
US Government Insured Loan Program [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, before Allowance for Credit Loss	811,700,000				811,700,000
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for credit losses				$ (528,000)		$ 445,000
Financing Receivable, before Allowance for Credit Loss	2,062,345,000				2,062,345,000		$ 1,395,036,000
Financing Receivable, Allowance for Credit Losses, Effect of Change in Method					(1,984,000)
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase					49,000
Loans and Leases Receivable, Allowance	$ (17,332,000)				$ (17,332,000)			$ (16,857,000)	$ (15,760,000)

Loans, Allowance for Loan Los_3

Loans, Allowance for Loan Losses and Credit Quality (ALLL - by category) (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							$ 8,809,155
Financing Receivable, Individually Evaluated for Impairment							49,628
Financing Receivable, after Allowance for Credit Loss							6,119,185
Summary of changes in allowance for loan losses
Beginning Balance			$ 67,740	$ 65,960	$ 67,740	$ 64,293
Charge-offs				707		(1,738)
Recoveries				1,689		2,387
Provision for credit losses	$ 7,500	$ 20,000	$ 25,000	0	52,500	2,000
Ending Balance	115,625			66,942	115,625	66,942
Ending Balance: Individually Evaluated for Impairment	837				837		980
Ending Balance: Collectively Evaluated for Impairment	66,105				66,105
Loans and Leases Receivable, Gross	9,405,193				9,405,193		8,873,639
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							1,370,580
Financing Receivable, Individually Evaluated for Impairment							24,456
Financing Receivable, after Allowance for Credit Loss							1,395,036
Summary of changes in allowance for loan losses
Beginning Balance				16,857		15,760
Charge-offs				0		0
Recoveries				1,003		1,127
Provision for credit losses				(528)		445
Ending Balance	17,332				17,332
Ending Balance: Individually Evaluated for Impairment	6				6		126
Ending Balance: Collectively Evaluated for Impairment	17,326				17,326
Financing Receivable, before Allowance for Credit Loss	2,062,345				2,062,345		1,395,036
Loans and Leases Receivable, Gross	2,062,345				2,062,345		1,395,036
Commercial Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							3,987,848
Financing Receivable, Individually Evaluated for Impairment							8,337
Financing Receivable, after Allowance for Credit Loss							4,002,359
Summary of changes in allowance for loan losses
Beginning Balance				32,660		32,370
Charge-offs				82		(82)
Recoveries				106		152
Provision for credit losses				(33)		211
Ending Balance	32,651				32,651
Ending Balance: Individually Evaluated for Impairment	41				41		48
Ending Balance: Collectively Evaluated for Impairment	32,610				32,610
Financing Receivable, before Allowance for Credit Loss	4,125,464				4,125,464		4,002,359
Loans and Leases Receivable, Gross	4,125,464				4,125,464		4,002,359
Construction Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							547,293
Financing Receivable, Individually Evaluated for Impairment							0
Financing Receivable, after Allowance for Credit Loss							547,293
Summary of changes in allowance for loan losses
Beginning Balance				5,593		5,158
Charge-offs				0		0
Recoveries				0		0
Provision for credit losses				240		675
Ending Balance	5,833				5,833
Ending Balance: Individually Evaluated for Impairment	0				0
Ending Balance: Collectively Evaluated for Impairment	5,833				5,833
Financing Receivable, before Allowance for Credit Loss	573,334				573,334		547,293
Loans and Leases Receivable, Gross	573,334				573,334		547,293
Small Business [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							173,960
Financing Receivable, Individually Evaluated for Impairment							537
Financing Receivable, after Allowance for Credit Loss							174,497
Summary of changes in allowance for loan losses
Beginning Balance				1,768		1,756
Charge-offs				125		(319)
Recoveries				61		108
Provision for credit losses				48		207
Ending Balance	1,752				1,752
Ending Balance: Individually Evaluated for Impairment	11				11		8
Ending Balance: Collectively Evaluated for Impairment	1,741				1,741
Financing Receivable, before Allowance for Credit Loss	167,632				167,632		174,497
Loans and Leases Receivable, Gross	167,632				167,632		174,497
Residential Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							1,571,848
Financing Receivable, Individually Evaluated for Impairment							11,228
Summary of changes in allowance for loan losses
Beginning Balance				3,296		3,219
Charge-offs				0		0
Recoveries				140		141
Provision for credit losses				(88)		(12)
Ending Balance	3,348				3,348
Ending Balance: Individually Evaluated for Impairment	619				619		637
Ending Balance: Collectively Evaluated for Impairment	2,729				2,729
Financing Receivable, before Allowance for Credit Loss	1,352,305				1,352,305		1,590,569
Loans and Leases Receivable, Gross	1,352,305				1,352,305		1,590,569
Consumer Home Equity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							1,127,963
Financing Receivable, Individually Evaluated for Impairment							4,948
Summary of changes in allowance for loan losses
Beginning Balance				5,547		5,608
Charge-offs				28		(212)
Recoveries				194		278
Provision for credit losses				36		75
Ending Balance	5,749				5,749
Ending Balance: Individually Evaluated for Impairment	155				155		156
Ending Balance: Collectively Evaluated for Impairment	5,594				5,594
Loans and Leases Receivable, Gross	1,101,054				1,101,054		1,133,798
Consumer - Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							29,663
Financing Receivable, Individually Evaluated for Impairment							122
Summary of changes in allowance for loan losses
Beginning Balance				239		422
Charge-offs				472		(1,125)
Recoveries				185		581
Provision for credit losses				$ 325		$ 399
Ending Balance	277				277
Ending Balance: Individually Evaluated for Impairment	5				5		5
Ending Balance: Collectively Evaluated for Impairment	272				272
Financing Receivable, before Allowance for Credit Loss	23,059				23,059		30,087
Loans and Leases Receivable, Gross	$ 23,059				$ 23,059		30,087	[1]
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							14,856
Financial Asset Acquired with Credit Deterioration [Member] | Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							0
Financial Asset Acquired with Credit Deterioration [Member] | Commercial Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							6,174
Financial Asset Acquired with Credit Deterioration [Member] | Construction Loans [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							0
Financial Asset Acquired with Credit Deterioration [Member] | Small Business [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							0
Financial Asset Acquired with Credit Deterioration [Member] | Residential Real Estate [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							7,493
Financial Asset Acquired with Credit Deterioration [Member] | Consumer Home Equity [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							887
Financial Asset Acquired with Credit Deterioration [Member] | Consumer - Other [Member]
Financing Receivable Impaired [Line Items]
Financing Receivable, after Allowance for Credit Loss							$ 302
[1]	Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances.

Loans, Allowance for Loan Los_4

Loans, Allowance for Loan Losses and Credit Quality (Internal Risk-Rating Categories for the Commercial Portfolio) (Details) $ in Thousands	Dec. 31, 2019USD ($)
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	$ 6,119,185
Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	1,395,036
Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	4,002,359
Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	547,293
Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	174,497
PASS [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	5,848,531
PASS [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	1,274,155
PASS [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	3,860,555
PASS [Member] | Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	542,608
PASS [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	171,213
POTENTIAL WEAKNESS [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	164,416
POTENTIAL WEAKNESS [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	63,485
POTENTIAL WEAKNESS [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	97,268
POTENTIAL WEAKNESS [Member] | Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	2,247
POTENTIAL WEAKNESS [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	1,416
DEFINITE WEAKNESS-LOSS UNLIKELY [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	106,238
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	57,396
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	44,536
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	2,438
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	1,868
PARTIAL LOSS PROBABLE [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
PARTIAL LOSS PROBABLE [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
PARTIAL LOSS PROBABLE [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
PARTIAL LOSS PROBABLE [Member] | Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
PARTIAL LOSS PROBABLE [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
DEFINITE LOSS [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
DEFINITE LOSS [Member] | Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
DEFINITE LOSS [Member] | Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
DEFINITE LOSS [Member] | Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	0
DEFINITE LOSS [Member] | Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
TOTAL	$ 0

Loans, Allowance for Loan Los_5

Loans, Allowance for Loan Losses and Credit Quality (Impaired Loans by Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 837	$ 980
Related Allowance		980
Impaired Financing Receivable, Recorded Investment, Total		49,628
Impaired Financing Receivable, Unpaid Principal Balance		68,140
WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		39,242
Unpaid Principal Balance		56,605
Related Allowance		0
WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		10,386
Unpaid Principal Balance		11,535
Commercial and Industrial [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	6	126
Commercial and Industrial [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		23,786
Unpaid Principal Balance		34,970
Related Allowance		0
Commercial and Industrial [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		670
Unpaid Principal Balance		670
Commercial Real Estate [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	41	48
Commercial Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		6,213
Unpaid Principal Balance		12,101
Related Allowance		0
Commercial Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		2,124
Unpaid Principal Balance		2,124
Construction Loans [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0
Small Business [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	11	8
Small Business [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		469
Unpaid Principal Balance		484
Related Allowance		0
Small Business [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		68
Unpaid Principal Balance		105
Residential Real Estate [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	619	637
Residential Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		4,976
Unpaid Principal Balance		5,123
Related Allowance		0
Residential Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		6,252
Unpaid Principal Balance		7,163
Consumer Home Equity [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	155	156
Consumer Home Equity [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		3,764
Unpaid Principal Balance		3,893
Related Allowance		0
Consumer Home Equity [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		1,184
Unpaid Principal Balance		1,382
Consumer - Other [Member]
Impaired loans by loan portfolio
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 5	5
Consumer - Other [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		34
Unpaid Principal Balance		34
Related Allowance		0
Consumer - Other [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Impaired loans by loan portfolio
Recorded Investment		88
Unpaid Principal Balance		$ 91

Loans, Allowance for Loan Los_6

Loans, Allowance for Loan Losses and Credit Quality (Int Inc. Recognized on Impaired Loans by Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Interest income recognized on impaired loans
Average Recorded Investment	$ 57,363	$ 60,120
Interest Income Recognized	392	1,214
WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	48,403	51,047
Interest Income Recognized	295	924
WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	8,960	9,073
Interest Income Recognized	97	290
Commercial and Industrial [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	25,694	27,937
Interest Income Recognized	35	108
Commercial and Industrial [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	353	360
Interest Income Recognized	4	13
Commercial Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	12,987	13,261
Interest Income Recognized	149	478
Commercial Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	1,402	1,415
Interest Income Recognized	20	60
Small Business [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	235	266
Interest Income Recognized	3	10
Small Business [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	92	95
Interest Income Recognized	0	2
Residential Real Estate [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	5,031	5,061
Interest Income Recognized	57	175
Residential Real Estate [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	6,047	6,115
Interest Income Recognized	61	179
Consumer Home Equity [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	4,417	4,479
Interest Income Recognized	50	151
Consumer Home Equity [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	959	972
Interest Income Recognized	11	33
Consumer - Other [Member] | WITH NO RELATED ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	39	43
Interest Income Recognized	1	2
Consumer - Other [Member] | WITH AN ALLOWANCE RECORDED: [Member]
Interest income recognized on impaired loans
Average Recorded Investment	107	116
Interest Income Recognized	$ 1	$ 3

Loans, Allowance for Loan Los_7

Loans, Allowance for Loan Losses and Credit Quality (Purchased Credit Impaired Loans - Outstanding/Carrying balances) (Details) $ in Thousands	Dec. 31, 2019USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Outstanding balance	$ 18,358
Financing Receivable, after Allowance for Credit Loss	6,119,185
Financial Asset Acquired with Credit Deterioration [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, after Allowance for Credit Loss	$ 14,856

Loans, Allowance for Loan Los_8

Loans, Allowance for Loan Losses and Credit Quality (Activity in the Accretable Yield for PCI loans) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019		Sep. 30, 2019
Loans, Allowance for Loan Losses and Credit Quality [Abstract]
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Additions	$ 0			$ 1,464
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Beginning of Period		$ 2,238		1,191
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion		(412)		(1,215)
Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow		237	[1]	623
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications (to) from Nonaccretable Difference		227		227
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, End of Period		$ 2,290		$ 2,290
[1]	(1) Represents changes in cash flows expected to be collected and resulting in increased interest income as a prospective yield adjustment over the remaining life of the loan(s).

Loans, Allowance for Loan Los_9

Loans, Allowance for Loan Losses and Credit Quality (Textual) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend					$ 2,100,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 0	$ 0	$ 0	$ 0
Days to be termed as non accrual loans			90 days
Tdrs Recorded Investment On Nonaccrual Status	$ 23,810,000		$ 23,810,000		$ 24,766,000

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses Finance Receivables Bifurcated by type of impairment evaluation (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		$ 8,809,155
Financing Receivable, Individually Evaluated for Impairment		49,628
Financing Receivable, after Allowance for Credit Loss		6,119,185
Loans and Leases Receivable, Gross	$ 9,405,193	8,873,639
Unamortized Loan Commitment and Origination fees		7,100
Unamortized Discounts or Premiums		21,600
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		1,370,580
Financing Receivable, Individually Evaluated for Impairment		24,456
Financing Receivable, after Allowance for Credit Loss		1,395,036
Financing Receivable, before Allowance for Credit Loss	2,062,345	1,395,036
Loans and Leases Receivable, Gross	2,062,345	1,395,036
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		3,987,848
Financing Receivable, Individually Evaluated for Impairment		8,337
Financing Receivable, after Allowance for Credit Loss		4,002,359
Financing Receivable, before Allowance for Credit Loss	4,125,464	4,002,359
Loans and Leases Receivable, Gross	4,125,464	4,002,359
Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		547,293
Financing Receivable, Individually Evaluated for Impairment		0
Financing Receivable, after Allowance for Credit Loss		547,293
Financing Receivable, before Allowance for Credit Loss	573,334	547,293
Loans and Leases Receivable, Gross	573,334	547,293
Small Business [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		173,960
Financing Receivable, Individually Evaluated for Impairment		537
Financing Receivable, after Allowance for Credit Loss		174,497
Financing Receivable, before Allowance for Credit Loss	167,632	174,497
Loans and Leases Receivable, Gross	167,632	174,497
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		1,571,848
Financing Receivable, Individually Evaluated for Impairment		11,228
Financing Receivable, before Allowance for Credit Loss	1,352,305	1,590,569
Loans and Leases Receivable, Gross	1,352,305	1,590,569
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		1,127,963
Financing Receivable, Individually Evaluated for Impairment		4,948
Loans and Leases Receivable, Gross	1,101,054	1,133,798
Consumer - Other [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Collectively Evaluated for Impairment		29,663
Financing Receivable, Individually Evaluated for Impairment		122
Financing Receivable, before Allowance for Credit Loss	23,059	30,087
Loans and Leases Receivable, Gross	$ 23,059	30,087	[1]
Financial Asset Acquired with Credit Deterioration [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		14,856
Financial Asset Acquired with Credit Deterioration [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		0
Financial Asset Acquired with Credit Deterioration [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		6,174
Financial Asset Acquired with Credit Deterioration [Member] | Construction Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		0
Financial Asset Acquired with Credit Deterioration [Member] | Small Business [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		0
Financial Asset Acquired with Credit Deterioration [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		7,493
Financial Asset Acquired with Credit Deterioration [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		887
Financial Asset Acquired with Credit Deterioration [Member] | Consumer - Other [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, after Allowance for Credit Loss		$ 302
[1]	Other consumer portfolio is inclusive of deposit account overdrafts recorded as loan balances.

Goodwill Schedule of Intangible

Goodwill Schedule of Intangible Assets and Goodwill table (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 506,206	$ 506,206
Intangible Assets, Net (Excluding Goodwill)	24,543	29,286
Intangible Assets, Net (Including Goodwill)	530,749	535,492
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Net (Excluding Goodwill)	23,625	28,016
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Net (Excluding Goodwill)	$ 918	$ 1,270

Earnings Per Share (EPS Compone

Earnings Per Share (EPS Components) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Summary of earnings per share
Net income	$ 34,873	$ 51,845	$ 86,526	$ 117,698
Weighted Average Shares (in shares)
BASIC SHARES	32,951,918	34,361,176	33,358,879	32,283,196
EFFECT OF DILUTIVE SECURITIES	24,758	39,390	27,871	45,416
DILUTIVE SHARES	32,976,676	34,400,566	33,386,750	32,328,612
NET INCOME PER SHARE (in dollars per share)
BASIC EPS	$ 1.06	$ 1.51	$ 2.59	$ 3.65
EFFECT OF DILUTIVE SECURITIES	0	0	0	(0.01)
DILUTIVE EPS	$ 1.06	$ 1.51	$ 2.59	$ 3.64

Earnings Per Share Antidilutive

Earnings Per Share Antidilutive Securities excluded from the Computaion of Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Option [Member]
Stock Option [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	10,000	5,000	10,000	0
Performance Shares [Member]
Stock Option [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	11,080	0

Stock Based Compensation (Award

Stock Based Compensation (Awards of Restricted Stock) (Details) - Restricted Stock [Member]	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Ratably Over Period [Member] | 2/27/2020 | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted | shares	46,550
Grant Date Fair Value Per Share | $ / shares	$ 70.24
Vesting Period	Ratably over 5 years from grant date
Ratably Over Period [Member] | 4/15/2020 | Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted | shares	880
Grant Date Fair Value Per Share | $ / shares	$ 68.14
Vesting Period	Ratably over 5 years from grant date
Immediate Vest on grant date [Member] | 5/27/2020 | Two Thousand Eighteen Nonemployee Director Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted | shares	9,438
Grant Date Fair Value Per Share | $ / shares	$ 72.86
Vesting Period	Shares vested immediately

Stock Based Compensation Perfor

Stock Based Compensation Performance-based Restricted Stock Textual (Details) - Employee Stock Plan [Member]	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted	17,100
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 70.24
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	100.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	14,400

Stock Based Compensation Stock

Stock Based Compensation Stock Based Compensation Option Awards Granted (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2020shares
Employee Stock Plan [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Derivative Positions for Interest Rate Swaps which Qualify as Hedges) (Details) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Amortization Of Deferred Hedge Gains Losses		$ 0		$ 0
Change in Fair Value on Loans Held for Sale		413,000	$ 272,000	1,252,000	$ 1,192,000
Fair Value Hedges, Net		0		0		$ 0
Interest rate collars on loans [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		$ 400,000,000		$ 400,000,000		$ 400,000,000
Derivative, Average Remaining Maturity				2 years 10 months 28 days		3 years 7 months 28 days
Derivative, Average Variable Interest Rate		0.15%		0.15%		1.76%
Fair Value	[1]	$ 24,169,000		$ 24,169,000		$ 9,896,000
Derivative, Average Cap Interest Rate		2.73%		2.73%		2.73%
Derivative, Average Floor Interest Rate		2.20%		2.20%		2.02%
Interest rate swaps on loans [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		$ 450,000,000		$ 450,000,000		$ 450,000,000
Derivative, Average Remaining Maturity				2 years 10 months 28 days		3 years 7 months 28 days
Derivative, Average Variable Interest Rate		0.15%		0.15%		1.76%
Derivative, Average Fixed Interest Rate		2.37%		2.37%		2.37%
Fair Value	[1]	$ 29,878,000		$ 29,878,000		$ 12,907,000
Interest rate swaps on borrowings [Member]
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		$ 75,000,000		$ 75,000,000		$ 75,000,000
Derivative, Average Remaining Maturity				1 year 5 months 4 days		2 years 2 months 4 days
Derivative, Average Variable Interest Rate		0.26%		0.26%		1.90%
Derivative, Average Fixed Interest Rate		1.53%		1.53%		1.53%
Fair Value	[1]	$ (1,561,000)		$ (1,561,000)		$ 140,000
Interest rate swaps
Details of derivative positions for interest rate swaps which qualify as hedges for accounting purposes
Derivative, Notional Amount		925,000,000		925,000,000		925,000,000
Fair Value	[1]	$ 52,486,000		$ 52,486,000		$ 22,943,000
[1]	Beginning in 2020, the Company made an election to include accrued interest within fair value balances.

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities (Customer Related Derivative Positions - Not Designated as Hedges) (Details) - Not Designated as Hedging Instrument $ in Thousands		Sep. 30, 2020USD ($)position	Dec. 31, 2019USD ($)position
Receive fixed, pay variable | Loan level swaps
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	331	299
Less than 1 year		$ 135,993	$ 156,690
Less than 2 years		34,017	125,203
Less than 3 years		158,477	85,603
Less than 4 years		138,314	165,599
Thereafter		1,260,159	1,044,315
Derivative, Notional Amount		1,726,960	1,577,410
Fair Value	[2]	$ 145,517	$ 48,596
Pay fixed, receive variable | Loan level swaps
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	322	290
Less than 1 year		$ 135,993	$ 156,690
Less than 2 years		34,017	125,203
Less than 3 years		158,477	85,603
Less than 4 years		138,314	165,599
Thereafter		1,260,159	1,044,315
Derivative, Notional Amount		1,726,960	1,577,410
Fair Value	[2]	$ (145,501)	$ (48,591)
Buys foreign currency, sells U.S. currency | Foreign exchange contracts
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	33	40
Less than 1 year		$ 81,207	$ 91,434
Derivative, Notional Amount		81,207	91,434
Fair Value	[2]	$ (3,125)	$ (81)
Buys U.S. currency, sells foreign currency | Foreign exchange contracts
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position	[1]	33	40
Less than 1 year		$ 81,207	$ 91,434
Derivative, Notional Amount		81,207	91,434
Fair Value	[2]	$ 3,151	$ 123
Risk Participated Out | Risk Participation Agreement
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position		13
Less than 1 year		$ 6,800
Less than 3 years		7,282
Thereafter		112,487
Derivative, Notional Amount		126,569
Fair Value		$ 745
Risk Participated In | Risk Participation Agreement
Summary of customer related derivative positions, not designated as hedging
Number of Positions | position		10
Less than 2 years		$ 18,978
Less than 3 years		23,925
Less than 4 years		36,836
Thereafter		18,295
Derivative, Notional Amount		98,034
Fair Value		$ (269)
[1]	The Company may enter into one dealer swap agreement which offsets multiple commercial borrower swap agreements.
[2]	Beginning in 2020, the Company made an election to include accrued interest within fair value balances.

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities (FV of Derivative Financial Instruments and Classification on Balance Sheet) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Asset	[1]	$ 210,754	$ 78,385
Derivative Liability	[2]	132,625	53,923
Derivative Asset, Fair Value, Amount Offset Against Collateral	[1]	156,707	53,503
Derivative, Collateral, Obligation to Return Securities	[1],[3]	54,047	24,882
Derivative, Collateral, Right to Reclaim Securities	[2],[3]	54,047	24,882
Derivative, Collateral, Obligation to Return Cash	[1]	0	0
Derivative, Collateral, Right to Reclaim Cash	[2]	73,094	25,493
Derivative Liability, Fair Value, Amount Offset Against Collateral	[2]	5,484	3,548
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	[1]	156,695	55,245
Derivative Asset, Fair Value, Gross Asset	[1]	210,742	78,385
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	[2]	150,052	53,726
Liability Derivatives	[2]	151,613	53,923
Interest rate swaps [Member] | Derivatives designated as hedges [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Interest Rate Derivative Assets, at Fair Value	[1],[4]	54,047	23,140
Interest rate swaps [Member] | Derivatives designated as hedges [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	[2],[5]	1,561	197
Loan level swaps [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1],[4]	145,517	52,374
Loan level swaps [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	[2],[5]	145,501	52,369
Foreign exchange contracts | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	3,785	1,191
Foreign exchange contracts | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	[2]	3,759	1,149
Interest Rate Lock Commitments [Member] | Not Designated as Hedging Instrument | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Instrument Not Designated as a Hedge, Interest Rate Lock Commitments, Asset at Fair Value	[1]	6,587	1,680
Derivative Instrument Not Designated as a Hedge, Forward Sales Agreements, Asset at Fair Value	[1]	61	0
Derivative Instrument Not Designated as a Hedge, Forward Sale Hedge Commitment, Asset at Fair Value	[1]	0	0
Interest Rate Lock Commitments [Member] | Not Designated as Hedging Instrument | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instrument Not Designated as a Hedge, Interest Rate Lock Commitments, Liabilities at Fair Value	[2]	0	0
Derivative Instrument Not Designated as a Hedge, Forward Sales Agreements, Liabilities at Fair Value	[2]	0	12
Derivative Instrument Not Designated as a Hedge, Forward Sale Hedge Commitment, Liability at Fair Value	[2]	523	196
CME [Member]
Derivatives, Fair Value [Line Items]
Derivative, Collateral, Obligation to Return Cash	[1],[6]	(12)	0
Derivative, Collateral, Right to Reclaim Cash	[2],[6]	18,988	0
Risk Participation Agreement | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Credit Risk Derivative Assets, at Fair Value		745	0
Risk Participation Agreement | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Credit Risk Derivative Liabilities, at Fair Value		$ 269	$ 0
[1]	All asset derivatives are located in other assets on the balance sheet.
[2]	All liability derivatives are located in other liabilities on the balance sheet.
[3]	Reflects offsetting derivative positions with the same counterparty that are not netted on the balance sheet.
[4]	Approximately $1.2 million and $1.9 million of accrued interest receivable is included in the fair value of the interest rate and loan level asset derivatives, respectively, as of September 30, 2020. Accrued interest receivable of approximately and $350,000 and $569,000 was excluded from the fair value of the interest rate and loan level asset derivatives, respectively, as of December 31, 2019.
[5]	Approximately $75,000 and $1.9 million of accrued interest payable is included in the fair value of the interest rate and loan level liability derivatives, respectively, as of September 30, 2020. Accrued interest payable of approximately $4,000 and $569,000 was excluded from the fair value of the interest rate and loan level derivative liabilities, respectively, as of December 31, 2019.
[6]	Netting adjustments represent the amounts recorded to convert derivative assets and liabilities cleared through CME from a gross basis to a net basis, inclusive of the variation margin payments, in accordance with applicable accounting guidance. As displayed in the table above, derivatives that cleared through the CME were either in a net asset position or a net liability position as of September 30, 2020.

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities (Derivative Financial Instruments included in OCI and Current Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, before Tax	$ (684)	$ 0	$ (684)	$ 0
Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Excluded Component, Gain (Loss), Recognized in Earnings	0	0
Gain reclassified from OCI into interest income or interest expense (effective portion)	4,339	352	9,901	1,170
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	2,020	374	4,647	1,937
Interest Expense [Member] | Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Excluded Component, Gain (Loss), Recognized in Earnings	0	0
Other expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	21	10	46	37
Changes in fair value of mortgage derivatives | Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Excluded Component, Gain (Loss), Recognized in Earnings	0	0
Changes in fair value of mortgage derivatives | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Other income	(28)	(2)	(52)	(13)
Total | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Mortgage banking income	2,027	366	4,653	1,913
Derivatives designated as hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	$ (2,729)	$ 3,030	$ 20,452	$ 14,905

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities (Textual) (Details) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Interest Receivable		$ (36,700,000)		$ (36,700,000)
Derivative, Net Liability Position, Aggregate Fair Value		93,000,000		$ 93,000,000		$ 26,000,000
Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge				4 years 1 month 6 days
Gain (Loss) on Sales of Loans, Net		10,000,000	$ 5,500,000	$ 20,700,000	$ 9,500,000
Exposure to Institutional Counterparties		54,000,000		54,000,000		25,400,000
Amortization Of Deferred Hedge Gains Losses		0		0
Customer related positions		145,500,000		145,500,000		51,000,000
Fair Value Hedges, Net		0		0		0
Change in Fair Value on Loans Held for Sale		413,000	272,000	1,252,000	1,192,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, before Tax		684,000	$ 0	684,000	$ 0
Interest rate swaps
Derivative [Line Items]
Interest Receivable	[1],[2]	(1,200,000)		(1,200,000)		(350,000)
Derivative, Notional Amount		925,000,000		925,000,000		925,000,000
Interest Payable, Current	[1],[2]	$ (75,000)		$ (75,000)		$ (4,000)
Interest rate collars on loans [Member]
Derivative [Line Items]
Derivative, Average Cap Interest Rate		2.73%		2.73%		2.73%
Derivative, Average Floor Interest Rate		2.20%		2.20%		2.02%
Derivative, Notional Amount		$ 400,000,000		$ 400,000,000		$ 400,000,000
Loan level swaps
Derivative [Line Items]
Interest Receivable	[1],[2]	(1,900,000)		(1,900,000)		(569,000)
Interest Payable, Current	[1],[2]	(1,900,000)		(1,900,000)		(569,000)
Interest rate swaps on borrowings [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 75,000,000		75,000,000		$ 75,000,000
Interest Income [Member]
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months				18,500,000
Interest Expense [Member]
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months				$ (999,000)
[1]	All asset derivatives are located in other assets on the balance sheet.
[2]	Approximately $1.2 million and $1.9 million of accrued interest receivable is included in the fair value of the interest rate and loan level asset derivatives, respectively, as of September 30, 2020. Accrued interest receivable of approximately and $350,000 and $569,000 was excluded from the fair value of the interest rate and loan level asset derivatives, respectively, as of December 31, 2019.

Income Taxes Tax Provision and

Income Taxes Tax Provision and Applicable Rates (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Tax provision and applicable tax rates [Line Items]
Current Federal, State and Local, Tax Expense (Benefit)	$ 11,199	$ 17,036	$ 21,126	$ 38,565
Effective Income Tax Rate Reconciliation, Percent	24.31%	24.73%	19.62%	24.68%

Income Taxes Textual (Details)

Income Taxes Textual (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Current Federal, State and Local, Tax Expense (Benefit)	$ 11,199	$ 17,036	$ 21,126	$ 38,565

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
ASSETS
Trading		$ 2,612	$ 2,179
Equity Securities, FV-NI		21,119	21,261
Debt Securities, Available-for-sale		423,478	426,424
U.S. government agency securities
ASSETS
Debt Securities, Available-for-sale		24,273	33,115
Agency mortgage-backed securities
ASSETS
Debt Securities, Available-for-sale		230,620	247,000
Pooled trust preferred securities issued by banks and insurers
ASSETS
Debt Securities, Available-for-sale		1,021	1,114
Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Available-for-sale		63,873	54,795
Recurring fair value measurements
ASSETS
Trading		2,612	2,179
LIABILITIES
TOTAL RECURRING FAIR VALUE MEASUREMENTS		561,051	507,633
Recurring fair value measurements | Equity Securities [Member]
ASSETS
Equity Securities, FV-NI		21,119	21,261
Recurring fair value measurements | U.S. government agency securities
ASSETS
Debt Securities, Available-for-sale		24,273	33,115
Recurring fair value measurements | Agency mortgage-backed securities
ASSETS
Debt Securities, Available-for-sale		230,620	247,000
Recurring fair value measurements | Agency collateralized mortgage obligations
ASSETS
Debt Securities, Available-for-sale		102,077	88,511
Recurring fair value measurements | Municipal Bonds [Member]
ASSETS
Debt Securities, Available-for-sale		1,145	1,396
Recurring fair value measurements | Single issuer trust preferred securities issued by banks and insurers
ASSETS
Debt Securities, Available-for-sale		469	493
Recurring fair value measurements | Pooled trust preferred securities issued by banks and insurers
ASSETS
Debt Securities, Available-for-sale		1,021	1,114
Recurring fair value measurements | Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Available-for-sale		63,873	54,795
Recurring fair value measurements | Loans held for sale
ASSETS
Loans Held-for-sale, Fair Value Disclosure		54,713	33,307
Recurring fair value measurements | Derivative Financial Instruments, Assets [Member]
ASSETS
Derivative Asset, Fair Value, Gross Asset		210,742	78,385
Recurring fair value measurements | Derivative instruments
LIABILITIES
Financial and Nonfinancial Liabilities, Fair Value Disclosure		151,613	53,923
Nonrecurring fair value measurements
LIABILITIES
TOTAL NONRECURRING FAIR VALUE MEASUREMENTS		56,660	25,515
Nonrecurring fair value measurements | Individually assessed collateral dependent loans
ASSETS
Assets, Fair Value Disclosure			25,515
Nonrecurring fair value measurements | Collateral Dependent Loans [Member]
ASSETS
Assets, Fair Value Disclosure		56,660
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring fair value measurements
ASSETS
Trading		2,612	2,179
LIABILITIES
TOTAL RECURRING FAIR VALUE MEASUREMENTS		23,731	23,440
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring fair value measurements | Equity Securities [Member]
ASSETS
Equity Securities, FV-NI		21,119	21,261
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring fair value measurements | Municipal Bonds [Member]
ASSETS
Debt Securities, Available-for-sale			0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring fair value measurements | Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Available-for-sale		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Nonrecurring fair value measurements
LIABILITIES
TOTAL NONRECURRING FAIR VALUE MEASUREMENTS		0	0
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements
LIABILITIES
TOTAL RECURRING FAIR VALUE MEASUREMENTS		536,299	483,079
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Equity Securities [Member]
ASSETS
Equity Securities, FV-NI		0	0
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | U.S. government agency securities
ASSETS
Debt Securities, Available-for-sale		24,273	33,115
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Agency mortgage-backed securities
ASSETS
Debt Securities, Available-for-sale		230,620	247,000
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Agency collateralized mortgage obligations
ASSETS
Debt Securities, Available-for-sale		102,077	88,511
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Municipal Bonds [Member]
ASSETS
Debt Securities, Available-for-sale		1,145	1,396
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Single issuer trust preferred securities issued by banks and insurers
ASSETS
Debt Securities, Available-for-sale		469	493
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Available-for-sale		63,873	54,795
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Loans held for sale
ASSETS
Loans Held-for-sale, Fair Value Disclosure		54,713	33,307
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Derivative Financial Instruments, Assets [Member]
ASSETS
Derivative Asset, Fair Value, Gross Asset		210,742	78,385
Significant Other Observable Inputs (Level 2) | Recurring fair value measurements | Derivative instruments
LIABILITIES
Financial and Nonfinancial Liabilities, Fair Value Disclosure		151,613	53,923
Significant Other Observable Inputs (Level 2) | Nonrecurring fair value measurements
LIABILITIES
TOTAL NONRECURRING FAIR VALUE MEASUREMENTS		0	0
Significant Unobservable Inputs (Level 3) | Recurring fair value measurements
LIABILITIES
TOTAL RECURRING FAIR VALUE MEASUREMENTS		1,021	1,114
Significant Unobservable Inputs (Level 3) | Recurring fair value measurements | Equity Securities [Member]
ASSETS
Equity Securities, FV-NI		0	0
Significant Unobservable Inputs (Level 3) | Recurring fair value measurements | Municipal Bonds [Member]
ASSETS
Debt Securities, Available-for-sale			0
Significant Unobservable Inputs (Level 3) | Recurring fair value measurements | Pooled trust preferred securities issued by banks and insurers
ASSETS
Debt Securities, Available-for-sale		1,021	1,114
Significant Unobservable Inputs (Level 3) | Recurring fair value measurements | Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Available-for-sale		0	0
Significant Unobservable Inputs (Level 3) | Nonrecurring fair value measurements
LIABILITIES
TOTAL NONRECURRING FAIR VALUE MEASUREMENTS		56,660	25,515
Significant Unobservable Inputs (Level 3) | Nonrecurring fair value measurements | Individually assessed collateral dependent loans
ASSETS
Assets, Fair Value Disclosure			$ 25,515
Significant Unobservable Inputs (Level 3) | Nonrecurring fair value measurements | Collateral Dependent Loans [Member]
ASSETS
Assets, Fair Value Disclosure	[1]	$ 56,660
[1]	Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary.

Fair Value Measurements (Deta_2

Fair Value Measurements (Details 1) - Pooled Trust Preferred Securities [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 1,021	$ 1,106	$ 1,021	$ 1,106	$ 986	$ 1,114	$ 1,281	$ 1,329
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	41	(14)	(38)	(38)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, (Sales), Issuances, (Settlements)	$ (6)	$ (161)	$ (55)	$ (185)

Fair Value Measurements (Deta_3

Fair Value Measurements (Details 2) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale		$ 423,478	$ 426,424
Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cumulative Default		11.90%	13.50%
Loss Given Default		94.00%	93.60%
Cure Given Default		60.90%	60.90%
Pooled trust preferred securities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale		$ 1,021	$ 1,114
Pooled trust preferred securities | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cumulative Default		4.00%	2.00%
Loss Given Default		85.00%	85.00%
Cure Given Default		0.00%	0.00%
Pooled trust preferred securities | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cumulative Default		100.00%	100.00%
Loss Given Default		100.00%	100.00%
Cure Given Default		75.00%	75.00%
Fair Value, Nonrecurring [Member] | Collateral Dependent Loans [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure		$ 56,660
Fair Value, Nonrecurring [Member] | Collateral Dependent Loans [Member] | Significant Unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure	[1]	$ 56,660
Fair Value, Nonrecurring [Member] | COLLATERAL DEPENDENT IMPAIRED LOANS [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure			$ 25,515
Fair Value, Nonrecurring [Member] | COLLATERAL DEPENDENT IMPAIRED LOANS [Member] | Significant Unobservable Inputs (Level 3)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assets, Fair Value Disclosure			$ 25,515
Measurement Input, Constant Prepayment Rate [Member] | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Weighted Average [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.026	0.026
Measurement Input, Constant Prepayment Rate [Member] | Pooled trust preferred securities | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0	0
Measurement Input, Constant Prepayment Rate [Member] | Pooled trust preferred securities | Discounted cash flow methodology [Member] | Significant Unobservable Inputs (Level 3) | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.56	0.57
[1]	Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary.

Fair Value Measurements (Deta_4

Fair Value Measurements (Details 3) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
ASSETS
Debt Securities, Held-to-maturity		$ 659,573	$ 740,806
Held to Maturity, Fair Value, Total		690,467	753,263
Loans, net of allowance for credit losses(b)		9,289,568	8,805,899
Federal Home Loan Bank Stock		15,090	14,424
Bank Owned Life Insurance		199,453	197,372
LIABILITIES
Federal Home Loan Bank borrowings(f)		145,765	115,748
Long-term Debt	[1]	37,447	74,906
Long-term Debt, Fair Value	[1]	36,448	72,219
Subordinated Debt		49,672	49,601
Deposits [Member]
LIABILITIES
Time certificates of deposits(f)	[2]	9,792,667	7,752,052
Accrued Liabilities, Fair Value Disclosure	[2]	9,792,667	7,752,052
Time certificates of deposits(f)
LIABILITIES
Time certificates of deposits(f)	[1]	1,058,641	1,395,315
Accrued Liabilities, Fair Value Disclosure	[1]	1,065,818	1,396,760
Federal Home Loan Bank borrowings(f)
LIABILITIES
Federal Home Loan Bank borrowings(f)	[1]	145,765	115,748
Federal Home Loan Bank Borrowings, Fair Value Disclosure	[1]	145,975	115,881
Junior subordinated debentures(g)
LIABILITIES
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	[3]	62,850	62,848
Accrued Liabilities, Fair Value Disclosure	[3]	67,883	65,603
Subordinated debentures(f)
LIABILITIES
Subordinated Debt	[1]	49,672	49,601
Accrued Liabilities, Fair Value Disclosure	[1]	47,173	52,870
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term Debt [Member]
LIABILITIES
Long-term Debt, Fair Value	[1]	0	0
Significant Other Observable Inputs (Level 2) | Deposits [Member]
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[2]	9,792,667	7,752,052
Significant Other Observable Inputs (Level 2) | Time certificates of deposits(f)
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[1]	1,065,818	1,396,760
Significant Other Observable Inputs (Level 2) | Federal Home Loan Bank borrowings(f)
LIABILITIES
Federal Home Loan Bank Borrowings, Fair Value Disclosure	[1]	145,975
Accrued Liabilities, Fair Value Disclosure	[1]		115,881
Significant Other Observable Inputs (Level 2) | Long-term Debt [Member]
LIABILITIES
Long-term Debt, Fair Value	[1]	36,448	72,219
Significant Other Observable Inputs (Level 2) | Junior subordinated debentures(g)
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[3]	67,883	65,603
Significant Unobservable Inputs (Level 3) | Long-term Debt [Member]
LIABILITIES
Long-term Debt, Fair Value	[1]	0	0
Significant Unobservable Inputs (Level 3) | Subordinated debentures(f)
LIABILITIES
Accrued Liabilities, Fair Value Disclosure	[1]	47,173	52,870
U.S. Government agency securities
ASSETS
Debt Securities, Held-to-maturity	[4]		12,874
Held to Maturity, Fair Value, Total	[4]		12,997
U.S. Government agency securities | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]		12,997
U.S. Treasury securities
ASSETS
Debt Securities, Held-to-maturity	[4]	4,021	4,032
Held to Maturity, Fair Value, Total	[4]	4,100	4,053
U.S. Treasury securities | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	4,100	4,053
Agency mortgage-backed securities
ASSETS
Debt Securities, Held-to-maturity	[4]	388,106	397,414
Held to Maturity, Fair Value, Total	[4]	407,793	405,802
Agency mortgage-backed securities | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	407,793	405,802
Agency collateralized mortgage obligations
ASSETS
Debt Securities, Held-to-maturity	[4]	237,380	293,662
Held to Maturity, Fair Value, Total	[4]	246,937	297,314
Agency collateralized mortgage obligations | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	246,937	297,314
Single issuer trust preferred securities issued by banks
ASSETS
Debt Securities, Held-to-maturity	[4]	1,500	1,500
Held to Maturity, Fair Value, Total	[4]	1,498	1,490
Single issuer trust preferred securities issued by banks | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	1,498	1,490
Small Business Administration Pooled Securities [Member]
ASSETS
Debt Securities, Held-to-maturity	[4]	28,566	31,324
Held to Maturity, Fair Value, Total	[4]	30,139	31,607
Small Business Administration Pooled Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Held to Maturity, Fair Value, Total	[4]	0	0
Small Business Administration Pooled Securities [Member] | Significant Other Observable Inputs (Level 2)
ASSETS
Held to Maturity, Fair Value, Total	[4]	30,139	31,607
Small Business Administration Pooled Securities [Member] | Significant Unobservable Inputs (Level 3)
ASSETS
Held to Maturity, Fair Value, Total	[4]	0	0
Loans, net of allowance for credit losses(b)
ASSETS
Loans, net of allowance for credit losses(b)	[5]	9,232,908	8,780,384
Loans Receivable, Fair Value Disclosure	[5]	9,185,023	8,613,635
Loans, net of allowance for credit losses(b) | Significant Unobservable Inputs (Level 3)
ASSETS
Loans Receivable, Fair Value Disclosure	[5]	9,185,023	8,613,635
Investment in Federal Home Loan Bank Stock [Member]
ASSETS
Federal Home Loan Bank Stock	[6]	15,090	14,424
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	15,090	14,424
Investment in Federal Home Loan Bank Stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	0	0
Investment in Federal Home Loan Bank Stock [Member] | Significant Other Observable Inputs (Level 2)
ASSETS
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	15,090	14,424
Investment in Federal Home Loan Bank Stock [Member] | Significant Unobservable Inputs (Level 3)
ASSETS
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	[6]	0	0
Cash Surrender Value [Member]
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	199,453	197,372
Bank Owned Life Insurance	[7]	199,453	197,372
Cash Surrender Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	0	0
Cash Surrender Value [Member] | Significant Other Observable Inputs (Level 2)
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	199,453	197,372
Cash Surrender Value [Member] | Significant Unobservable Inputs (Level 3)
ASSETS
Cash Surrender Value, Fair Value Disclosure	[7]	$ 0	$ 0
[1]	Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities.
[2]	Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date.
[3]	Fair value was determined based upon market prices of securities with similar terms and maturities.
[4]	The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis.
[5]	Fair value of loans is measured using the exit price valuation method, determined primarily by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows, while incorporating liquidity and credit assumptions. Additionally, this amount excludes individually assessed collateral dependent loans, which are deemed to be marked to fair value on a nonrecurring basis.
[6]	Federal Home Loan Bank stock has no quoted market value and is carried at cost; therefore the carrying amount approximates fair value.
[7]	Cash surrender value of life insurance policies is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore, carrying amount approximates fair value.

Revenue Recognition Disaggregat

Revenue Recognition Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Other noninterest income - ASC 606	$ 905	$ 1,487	$ 2,651	$ 4,068
Total noninterest income in scope of ASC 606	15,183	20,056	49,661	56,710
Total noninterest income out of scope of ASC 606	14,164	11,760	34,311	25,287
Noninterest Income	29,347	31,816	83,972	81,997
Deposit Account [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3,428	5,299	11,227	14,785
Credit Card, Merchant Discount [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,025	4,913	10,665	13,473
ATM Charge [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	708	939	1,872	2,461
Investment Advisory, Management and Administrative Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	6,997	6,635	20,113	19,127
Investment Advisory, Retail Investment and Insurance Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	574	553	1,583	1,962
Merchant Processing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	330	230	1,000	834
Credit Card Income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 216	$ 0	$ 550	$ 0

Revenue Recognition Contract wi

Revenue Recognition Contract with Customer, Asset (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Investment Management Income Receivable	$ 4,383	$ 2,341

Comprehensive Income_Loss (Comp

Comprehensive Income/Loss (Comprehensive Income/(Loss) Presented Net of Taxes) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax		$ (3,798)	$ 4,216	$ 28,457	$ 20,743
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), after Adjustments, Tax		1,069	(1,186)	(8,005)	(5,838)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax		(2,729)	3,030	20,452	14,905
COMPREHENSIVE INCOME
Change in fair value of securities available for sale, pre tax amount		(857)	2,858	13,598	14,699
Change in fair value of securities available for sale, tax (expense) benefit		148	(683)	(3,265)	(3,401)
Change in fair value of securities available for sale, after tax amount		(709)	2,175	10,333	11,298
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax		0	0	0	(1,462)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax		0	0	0	411
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		0	0	0	(1,051)
Change in fair value of securities available for sale, pre tax amount		(857)	2,858	13,598	16,161
Change in fair value of securities available for sale, tax (expense) benefit		148	(683)	(3,265)	(3,812)
Change in fair value of securities available for sale, after tax amount		(709)	2,175	10,333	12,349
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax		(143)	4,568	37,674	21,913
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax		41	(1,285)	(10,597)	(6,167)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax		(102)	3,283	27,077	15,746
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax		4,339	352	9,901	1,170
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), Adjustments, Tax		(1,220)	(99)	(2,784)	(329)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax		3,119	253	7,117	841
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, After Tax		(492)		(492)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derviatives, Tax		(192)		(192)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax		(2)	(11)	(1,392)	(33)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax		1	3	392	9
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax		(1)	(8)	(1,000)	(24)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		245	(2)	736	(6)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax		(69)	1	(207)	2
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		176	(1)	529	(4)
Amortization of certain costs included in net periodic retirement costs, pre tax amount		69	69	207	207
Amortization of certain costs included in net periodic retirement costs, tax (expense) benefit		(19)	(19)	(58)	(58)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax		50	50	149	149
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[1]	312	56	(449)	168
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	[1]	(87)	(15)	127	(47)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	[1]	225	41	(322)	121
Total other comprehensive income, pre tax amount		(4,343)	7,130	41,606	37,072
Total other comprehensive income, tax (expense) benefit		1,130	(1,884)	(11,143)	(9,697)
Total other comprehensive income, after tax amount		(3,213)	5,246	30,463	27,375
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, before Tax		(684)	0	(684)	0
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, before Tax		(684)	$ 0	(684)	$ 0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derviatives, Tax		(192)		(192)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Loss on Termination of Derivatives, After Tax		$ (492)		$ (492)
[1]	The following tables present a reconciliation of the changes in the components of other comprehensive income (loss) for the periods indicated, including the amount of income tax (expense) benefit allocated to each component of other comprehensive income (loss): Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ (857) $ 148 $ (709) $ 13,598 $ (3,265) $ 10,333 Less: net security losses reclassified into other noninterest expense — — — — — — Net change in fair value of securities available for sale (857) 148 (709) 13,598 (3,265) 10,333 Change in fair value of cash flow hedges (143) 41 (102) 37,674 (10,597) 27,077 Less: net cash flow hedge gains reclassified into interest income or interest expense 4,339 (1,220) 3,119 9,901 (2,784) 7,117 Less: Loss on termination of hedge reclassified into noninterest expense (684) 192 (492) (684) 192 (492) Net change in fair value of cash flow hedges (3,798) 1,069 (2,729) 28,457 (8,005) 20,452 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (2) 1 (1) (1,392) 392 (1,000) Amortization of net actuarial losses 245 (69) 176 736 (207) 529 Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 312 (87) 225 (449) 127 (322) Total other comprehensive income (loss) $ (4,343) $ 1,130 $ (3,213) $ 41,606 $ (11,143) $ 30,463 Three Months Ended Nine Months Ended Pre Tax Tax (Expense) After Tax Pre Tax Tax (Expense) After Tax (Dollars in thousands) Change in fair value of securities available for sale $ 2,858 $ (683) $ 2,175 $ 14,699 $ (3,401) $ 11,298 Less: net security losses reclassified into other noninterest expense — — — (1,462) 411 (1,051) Net change in fair value of securities available for sale 2,858 (683) 2,175 16,161 (3,812) 12,349 Change in fair value of cash flow hedges 4,568 (1,285) 3,283 21,913 (6,167) 15,746 Less: net cash flow hedge gains reclassified into interest income or interest expense 352 (99) 253 1,170 (329) 841 Net change in fair value of cash flow hedges 4,216 (1,186) 3,030 20,743 (5,838) 14,905 Net unamortized loss related to defined benefit pension and other postretirement adjustments arising during the period (11) 3 (8) (33) 9 (24) Amortization of net actuarial gains (2) 1 (1) (6) 2 (4) Amortization of net prior service costs 69 (19) 50 207 (58) 149 Net change in other comprehensive income for defined benefit postretirement plans (1) 56 (15) 41 168 (47) 121 Total other comprehensive income $ 7,130 $ (1,884) $ 5,246 $ 37,072 $ (9,697) $ 27,375 (1) The amortization of prior service costs is included in the computation of net periodic pension cost as disclosed in the Employee Benefit Plans footnote in the Company's Annual Report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission.

Comprehensive Income_Loss (Co_2

Comprehensive Income/Loss (Comprised of the following Components) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 18,169	$ (1,173)
Net change in other comprehensive income (loss)	$ (3,213)	$ 5,246	30,463	27,375
Ending Balance	48,632	26,202	48,632	26,202
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			4,398	(5,947)
Net change in other comprehensive income (loss)			10,333	12,349
Ending Balance	14,731	6,402	14,731	6,402
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			16,479	6,148
Net change in other comprehensive income (loss)			20,452	14,905
Ending Balance	36,931	21,053	36,931	21,053
Defined Benefit Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(2,708)	(1,374)
Net change in other comprehensive income (loss)			(322)	121
Ending Balance	(3,030)	(1,253)	(3,030)	(1,253)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change in other comprehensive income (loss)	$ (3,213)	$ 5,246	$ 30,463	$ 27,375

Commitments and contingencies F

Commitments and contingencies Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 3,258,341	$ 3,337,930
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	20,902	21,565
Deferred standby letter of credit fees [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	191	158
Obligation to Repurchase Receivables Sold [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 343,314	$ 404,532

Commitments and contingencies T

Commitments and contingencies Textual (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Cash Reserve Deposit Required and Made	$ 0	$ 0
Minimum [Member]
Lessee, Operating Lease, Renewal Term	1 year
Maximum [Member]
Lessee, Operating Lease, Renewal Term	10 years

Uncategorized Items - indb-2020

Label	Element	Value
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	$ 32,777,000	[1]
Operating Lease, Right-of-Use Asset	us-gaap_OperatingLeaseRightOfUseAsset	32,800,000	[1]
Operating Lease, Liability	us-gaap_OperatingLeaseLiability	34,100,000
Deferred Rent Credit	us-gaap_DeferredRentCredit	$ 1,300,000
[1]	Represents adjustment needed to reflect the opening balance of the Company's Right of Use ("ROU") assets and lease liabilities pursuant to the adoption of Accounting Standards Update 2016-02 effective January 1, 2019. Upon adoption, the Company recognized on its balance sheet ROU assets of approximately $32.8 million, with a corresponding operating lease liability of approximately $34.1 million, with an adjustment to remove the Company's existing deferred rent liability of approximately $1.3 million.