BankUnited (BKU) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 26, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	BankUnited, Inc.
Entity Central Index Key	1,504,008
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock Shares Outstanding		106,017,421
Entity Public Float			$ 3,551,584,938
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Cash and due from banks:
Non-interest bearing	$ 35,246	$ 40,260
Interest bearing	159,336	408,053
Cash and cash equivalents	194,582	448,313
Investment securities available for sale, at fair value	6,680,832	6,073,584
Investment securities held to maturity	10,000	10,000
Non-marketable equity securities	265,989	284,272
Loans held for sale	34,097	41,198
Loans (including covered loans of $503,118 and $614,042)	21,416,504	19,395,394
Allowance for loan and lease losses	(144,795)	(152,953)
Loans, net	21,271,709	19,242,441
FDIC indemnification asset	295,635	515,933
Bank owned life insurance	252,462	239,736
Equipment under operating lease, net	599,502	539,914
Goodwill and other intangible assets	77,796	78,047
Other assets	664,382	406,713
Total assets	30,346,986	27,880,151
Demand deposits:
Non-interest bearing	3,162,032	2,960,591
Interest bearing	1,666,581	1,523,064
Savings and money market	10,715,024	9,251,593
Time Deposits	6,334,842	5,755,642
Total deposits	21,878,479	19,490,890
Federal Home Loan Bank advances	4,771,000	5,239,348
Notes and other borrowings	402,830	402,809
Other liabilities	268,615	328,675
Total liabilities	27,320,924	25,461,722
Commitments and contingencies
Stockholders' equity:
Common stock, par value $0.01 per share, 400,000,000 shares authorized; 106,848,185 and 104,166,945 shares issued and outstanding	1,068	1,042
Paid-in capital	1,498,227	1,426,459
Retained earnings	1,471,781	949,681
Accumulated other comprehensive income	54,986	41,247
Total stockholders' equity	3,026,062	2,418,429
Total liabilities and stockholders' equity	$ 30,346,986	$ 27,880,151

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Covered loans net of premiums, discounts and deferred fees and costs	$ 503,118	$ 614,042
Stockholders' equity:
Common stock, par value (in Dollars per Share)	$ 0.01	$ 0.01
Common stock, shares authorized (in Shares)	400,000,000	400,000,000
Common stock, shares issued (in Shares)	106,848,185	104,166,945
Common stock, shares outstanding (in Shares)	106,848,185	104,166,945

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Loans	$ 1,001,862	$ 896,154	$ 753,901
Investment Securities	188,307	150,859	116,817
Other	14,292	12,204	10,098
Total interest income	1,204,461	1,059,217	880,816
Interest expense:
Deposits	170,933	119,773	91,151
Borrowings	83,256	69,059	44,013
Total interest expense	254,189	188,832	135,164
Net interest income before provision for loan losses	950,272	870,385	745,652
Provision for loan losses	68,747	50,911	44,311
Net interest income after provision for loan losses	881,525	819,474	701,341
Non-interest income:
Income from resolution of covered assets, net	27,450	36,155	50,658
Net loss on FDIC indemnification	(22,220)	(17,759)	(65,942)
Service charges and fees	20,864	19,463	17,876
Gain (loss) on sale of loans, net (including $17,406, $(14,470) and $34,929 related to covered loans)	27,589	(4,406)	40,633
Gain on investment securities available for sale, net	33,466	14,461	8,480
Lease financing	53,837	44,738	35,641
Other non-interest income	16,918	13,765	14,878
Total non-interest income	157,904	106,417	102,224
Non-interest expense:
Employee compensation and benefits	237,824	223,011	210,104
Occupancy and equipment	75,386	76,003	76,024
Amortization of FDIC indemnification asset	176,466	160,091	109,411
Deposit insurance expense	22,011	17,806	14,257
Professional fees	23,676	14,249	14,185
Telecommunications and data processing	13,966	14,343	13,613
Depreciation of equipment under operating lease	35,015	31,580	18,369
Other non-interest expense	50,624	53,364	50,709
Total non-interest expense	634,968	590,447	506,672
Income before income taxes	404,461	335,444	296,893
Provision (benefit) for income taxes	(209,812)	109,703	45,233
Net income	$ 614,273	$ 225,741	$ 251,660
Earnings Per Share, Basic	$ 5.60	$ 2.11	$ 2.37
Earnings Per Share, Diluted	5.58	2.09	2.35
Cash dividends declared per common share (in Dollars per Share)	$ 0.84	$ 0.84	$ 0.84

CONSOLIDATED STATEMENTS OF INC5

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Provision for (recovery of) losses on covered loans	$ 5,174	$ 37,854	$ 13,619	$ 12,100	$ 8,462	$ 24,408	$ 14,333	$ 3,708	$ 68,747	$ 50,911	$ 44,311
Non-interest income:
Gain (Loss) on Sale of Covered Loans									27,589	(4,406)	40,633
Covered [Member]
Provision for (recovery of) losses on covered loans									1,358	(1,681)	2,251
Non-interest income:
Gain (Loss) on Sale of Covered Loans									$ 17,406	$ (14,470)	$ 34,929

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 417,794	$ 67,779	$ 66,407	$ 62,293	$ 63,294	$ 50,848	$ 56,725	$ 54,874	$ 614,273	$ 225,741	$ 251,660
Unrealized gains on investment securities available for sale:
Net unrealized holding gain (loss) arising during the period									29,724	14,271	(21,657)
Reclassification adjustment for net securities gains realized in income									(20,247)	(8,749)	(5,130)
Net change in unrealized gains on securities available for sale									9,477	5,522	(26,787)
Unrealized losses on derivative instruments:
Net unrealized holding gain (loss) arising during the period									(1,559)	3,766	(13,403)
Reclassification adjustment for net losses realized in income									5,821	9,777	16,020
Net change in unrealized losses on derivative instruments									4,262	13,543	2,617
Other comprehensive income (loss)									13,739	19,065	(24,170)
Comprehensive income									$ 628,012	$ 244,806	$ 227,490

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 614,273	$ 225,741	$ 251,660
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and accretion, net	(95,145)	(113,979)	(164,376)
Provision for loan losses	68,747	50,911	44,311
Income from resolution of covered assets, net	(27,450)	(36,155)	(50,658)
Net loss on FDIC indemnification	22,220	17,759	65,942
(Gain) loss on sale of loans, net	(27,589)	4,406	(40,633)
Income from bank owned life insurance	(5,508)	(3,469)	(3,102)
Gain on investment securities available for sale, net	(33,466)	(14,461)	(8,480)
Equity based compensation	22,692	18,032	16,027
Depreciation and amortization	61,552	56,444	43,390
Deferred income taxes	57,801	30,189	29,471
Proceeds from sale of loans held for sale	158,621	163,088	169,139
Loans originated for sale, net of repayments	(142,682)	(148,195)	(130,819)
Other:
(Increase) decrease in other assets	(314,121)	24,840	(34,315)
Increase (decrease) in other liabilities	(41,319)	33,359	31,922
Net cash provided by operating activities	318,626	308,510	219,479
Net Cash Provided by (Used in) Investing Activities [Abstract]
Business Combination, Consideration Transferred	0	0	(277,553)
Purchase of investment securities available for sale	(3,131,798)	(3,058,106)	(2,093,508)
Proceeds from repayments and calls of investment securities available for sale	1,260,444	724,666	537,992
Proceeds from sale of investment securities available for sale	1,287,591	1,127,983	1,114,020
Purchase of non-marketable equity securities	(248,405)	(255,100)	(141,599)
Proceeds from redemption of non-marketable equity securities	266,688	190,825	113,276
Purchases of loans	(1,300,996)	(1,266,097)	(787,834)
Loan originations, repayments and resolutions, net	(672,338)	(1,394,916)	(3,128,701)
Proceeds from sale of loans, net	196,413	171,367	207,425
Decrease in FDIC indemnification asset for claims filed	21,589	46,083	59,139
Acquisition of equipment under operating lease, net	(94,603)	(87,976)	(187,329)
Other investing activities	(37,161)	(24,960)	(24,020)
Net cash used in investing activities	(2,452,576)	(3,826,231)	(4,608,692)
Cash flows from financing activities:
Net increase in deposits	2,387,589	2,552,389	3,426,755
Additions to Federal Home Loan Bank advances	4,916,000	4,025,000	3,180,000
Repayments of Federal Home Loan Bank advances	(5,385,000)	(2,795,000)	(2,480,350)
Proceeds from Issuance of Long-term Debt	0	0	392,252
Dividends paid	(91,628)	(89,824)	(88,981)
Exercise of stock options	62,095	791	35,647
Other financing activities	(8,837)	5,178	3,873
Net cash provided by financing activities	1,880,219	3,698,534	4,469,196
Net increase (decrease) in cash and cash equivalents	(253,731)	180,813	79,983
Cash and cash equivalents, beginning of period	448,313	267,500	187,517
Cash and cash equivalents, end of period	194,582	448,313	267,500
Supplemental Cash Flow Information [Abstract]
Interest paid	247,548	186,525	130,963
Income taxes paid, net	69,231	16,464	29,346
Supplemental schedule of non-cash investing and financing activities:
Transfers from loans to other real estate owned and other repossessed assets	13,313	17,045	17,541
Dividends declared, not paid	23,055	22,510	22,380
Obligations incurred in acquisition of affordable housing limited partnerships	$ 0	$ 12,750	$ 57,139

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Balance (in Shares) at Dec. 31, 2014		101,656,702
Balance at Dec. 31, 2014	$ 2,052,534	$ 1,017	$ 1,353,538	$ 651,627	$ 46,352
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	227,490			251,660	(24,170)
Dividends	(89,393)			(89,393)
Equity based compensation (in Shares)		664,928
Equity based compensation	$ 16,027	$ 7	16,020
Forfeiture of unvested shares (in Shares)		(59,270)
Forfeiture of unvested shares and shares surrendered for tax withholding obligations		$ (1)	1
Exercise of stock options (in Shares)	1,363,895	1,363,895
Exercise of stock options	$ 35,647	$ 13	35,634
Tax benefits from dividend equivalents and equity based compensation	1,593		1,593
Balance (in Shares) at Dec. 31, 2015		103,626,255
Balance at Dec. 31, 2015	2,243,898	$ 1,036	1,406,786	813,894	22,182
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	244,806			225,741	19,065
Dividends	(89,954)			(89,954)
Equity based compensation (in Shares)		651,760
Equity based compensation	18,033	$ 7	18,026
Forfeiture of unvested shares (in Shares)		(159,049)
Forfeiture of unvested shares and shares surrendered for tax withholding obligations	$ (485)	$ (1)	(484)
Exercise of stock options (in Shares)	47,979	47,979
Exercise of stock options	$ 791	$ 0	791
Tax benefits from dividend equivalents and equity based compensation	1,340		1,340
Balance (in Shares) at Dec. 31, 2016		104,166,945
Balance at Dec. 31, 2016	2,418,429	$ 1,042	1,426,459	949,681	41,247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	628,012			614,273	13,739
Dividends	(92,173)			(92,173)
Equity based compensation (in Shares)		621,806
Equity based compensation	16,996	$ 6	16,990
Forfeiture of unvested shares (in Shares)		(271,954)
Forfeiture of unvested shares and shares surrendered for tax withholding obligations	$ (7,297)	$ (3)	(7,294)
Exercise of stock options (in Shares)	2,331,388	2,331,388
Exercise of stock options	$ 62,095	$ 23	62,072
Balance (in Shares) at Dec. 31, 2017		106,848,185
Balance at Dec. 31, 2017	$ 3,026,062	$ 1,068	$ 1,498,227	$ 1,471,781	$ 54,986

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Summary of Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2017
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation and Summary of Significant Accounting Policies BankUnited, Inc. is a national bank holding company with one wholly-owned subsidiary, BankUnited; collectively, the Company. BankUnited, a national banking association headquartered in Miami Lakes, Florida, provides a full range of banking and related services to individual and corporate customers through 87 banking centers located in 15 Florida counties and 6 banking centers located in the New York metropolitan area at December 31, 2017 . The Bank also offers certain commercial lending and deposit products through national platforms. In connection with the FSB Acquisition, BankUnited entered into two loss sharing agreements with the FDIC. The Loss Sharing Agreements consist of the Single Family Shared-Loss Agreement and the Commercial Shared-Loss Agreement. Assets covered by the Loss Sharing Agreements are referred to as covered assets or, in certain cases, covered loans. The Single Family Shared-Loss Agreement provides for FDIC loss sharing and the Bank’s reimbursement for recoveries to the FDIC through May 21, 2019 for single family residential loans and OREO. Loss sharing under the Commercial Shared-Loss Agreement terminated on May 21, 2014. The Commercial Shared-Loss Agreement continued to provide for the Bank’s reimbursement of recoveries to the FDIC through June 30, 2017 for all other covered assets, including commercial real estate, commercial and industrial and consumer loans, certain investment securities and commercial OREO. Pursuant to the terms of the Loss Sharing Agreements, the covered assets are subject to a stated loss threshold whereby the FDIC will reimburse BankUnited for 80% of losses related to the covered assets up to $4.0 billion and 95% of losses in excess of this amount, beginning with the first dollar of loss incurred. The consolidated financial statements have been prepared in accordance with GAAP and prevailing practices in the banking industry. The Company has a single reportable segment. Accounting Estimates In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, and expenses and disclosures of contingent assets and liabilities. Actual results could differ significantly from these estimates. Significant estimates include the ALLL, the amount and timing of expected cash flows from covered assets and the FDIC indemnification asset, and the fair values of investment securities and other financial instruments. Management has used information provided by third party valuation specialists to assist in the determination of the fair values of investment securities. Principles of Consolidation The consolidated financial statements include the accounts of BankUnited, Inc. and its wholly-owned subsidiary. All significant intercompany balances and transactions have been eliminated in consolidation. VIEs are consolidated if the Company is the primary beneficiary; i.e., has (i) the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and (ii) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company has variable interests in affordable housing limited partnerships that are not required to be consolidated because the Company is not the primary beneficiary. Fair Value Measurements Certain of the Company's assets and liabilities are reflected in the financial statements at fair value on either a recurring or non-recurring basis. Investment securities available for sale, servicing rights and derivative instruments are measured at fair value on a recurring basis. Assets measured at fair value or fair value less cost to sell on a non-recurring basis may include collateral dependent impaired loans, OREO and other repossessed assets, loans held for sale, goodwill, impaired long-lived assets and assets acquired and liabilities assumed in business combinations. These non-recurring fair value measurements typically involve the application of acquisition accounting, lower-of-cost-or-market accounting or the measurement of impairment of certain assets. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. GAAP establishes a hierarchy that prioritizes inputs used to determine fair value measurements into three levels based on the observability and transparency of the inputs: • Level 1 inputs are unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities. • Level 2 inputs are observable inputs other than level 1 inputs, including quoted prices for similar assets and liabilities, quoted prices for identical assets and liabilities in less active markets and other inputs that can be corroborated by observable market data. • Level 3 inputs are unobservable inputs supported by limited or no market activity or data and inputs requiring significant management judgment or estimation. The fair value hierarchy requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs in estimating fair value. Unobservable inputs are utilized in determining fair value measurements only to the extent that observable inputs are unavailable. The need to use unobservable inputs generally results from a lack of market liquidity and diminished observability of actual trades or assumptions that would otherwise be available to value a particular asset or liability. Transfers between levels of the fair value hierarchy are recorded as of the end of the reporting period. Cash and Cash Equivalents Cash and cash equivalents include cash and due from banks, both interest bearing and non-interest bearing, including amounts on deposit at the Federal Reserve Bank, and federal funds sold. Cash equivalents have original maturities of three months or less. For purposes of reporting cash flows, cash receipts and payments pertaining to FHLB advances with original maturities of three months or less are reported net. Investment Securities Debt securities that the Company has the positive intent and ability to hold to maturity are classified as held to maturity and reported at amortized cost. Debt securities that the Company may not have the intent to hold to maturity and marketable equity securities are classified as available for sale at the time of acquisition and carried at fair value with unrealized gains and losses, net of tax, excluded from earnings and reported in AOCI, a separate component of stockholders' equity. Securities classified as available for sale may be used as part of the Company's asset/liability management strategy and may be sold in response to liquidity needs, regulatory changes, changes in interest rates, prepayment risk or other market factors. The Company does not maintain a trading portfolio. Purchase premiums and discounts on debt securities are amortized as adjustments to yield over the expected lives of the securities, using the level yield method. Premiums are amortized to the call date if the call is considered to be clearly and closely related to the host contract. Realized gains and losses from sales of securities are recorded on the trade date and are determined using the specific identification method. The Company reviews investment securities for OTTI at least quarterly. An investment security is impaired if its fair value is lower than its amortized cost basis. The Company considers many factors in determining whether a decline in fair value below amortized cost represents OTTI, including, but not limited to: • the Company's intent to hold the security until maturity or for a period of time sufficient for a recovery in value; • whether it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis; • the length of time and extent to which fair value has been less than amortized cost; • adverse changes in expected cash flows; • collateral values and performance; • the payment structure of the security including levels of subordination or over-collateralization; • changes in the economic or regulatory environment; • the general market condition of the geographic area or industry of the issuer; • the issuer's financial condition, performance and business prospects; and • changes in credit ratings. The relative importance assigned to each of these factors varies depending on the facts and circumstances pertinent to the individual security being evaluated. The Company recognizes OTTI of a debt security for which there has been a decline in fair value below amortized cost if (i) management intends to sell the security, (ii) it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, or (iii) the Company does not expect to recover the entire amortized cost basis of the security. If the Company intends to sell the security, or if it is more likely than not it will be required to sell the security before recovery, an OTTI write-down is recognized in earnings equal to the entire difference between the amortized cost basis and fair value of the security. Otherwise, the amount by which amortized cost exceeds the fair value of a debt security that is considered to be other-than-temporarily impaired is separated into a component representing the credit loss, which is recognized in earnings, and a component related to all other factors, which is recognized in other comprehensive income. The measurement of the credit loss component is equal to the difference between the debt security's amortized cost basis and the present value of its expected future cash flows discounted at the security's effective yield. The evaluation of OTTI of marketable equity securities focuses on whether evidence supports recovery of the unrealized loss within a timeframe consistent with temporary impairment. The entire amount by which cost basis exceeds the fair value of an equity security that is considered to be other-than-temporarily impaired is recognized in earnings. Non-marketable Equity Securities The Bank, as a member of the FRB system and the FHLB, is required to maintain investments in the stock of the FRB and FHLB. No market exists for this stock, and the investment can be liquidated only through redemption by the respective institutions, at the discretion of and subject to conditions imposed by those institutions. The stock has no readily determinable fair value and is carried at cost. Historically, stock redemptions have been at par value, which equals the Company's carrying value. The Company monitors its investment in FHLB stock for impairment through review of recent financial results of the FHLB, including capital adequacy and liquidity position, dividend payment history, redemption history and information from credit agencies. The Company has not identified any indicators of impairment of FHLB stock. Loans Held for Sale The guaranteed portion of SBA and USDA loans originated with the intent to sell are carried at the lower of cost or fair value, determined in the aggregate. A valuation allowance is established through a charge to earnings if the aggregate fair value of such loans is lower than their cost. Gains or losses recognized upon sale are determined on the specific identification basis. Loans not originated or otherwise acquired with the intent to sell are transferred into the held for sale classification at the lower of carrying amount or fair value when they are specifically identified for sale and a formal plan exists to sell them. Acquired credit impaired loans accounted for in pools are removed from the pools at their carrying amounts when they are sold. Loans The Company's loan portfolio contains 1-4 single family residential first mortgages, home equity loans and lines of credit, consumer, multi-family, owner and non-owner occupied commercial real estate, construction and land, and commercial and industrial loans, mortgage warehouse lines of credit and direct financing leases. The Company segregates its loan portfolio between covered and non-covered loans. Covered loans are loans acquired from the FDIC in the FSB Acquisition that are covered under the Single Family Shared-Loss Agreement. Covered loans are further segregated between ACI loans and non-ACI loans. Non-covered Loans Non-covered loans, other than non-covered ACI loans, are carried at UPB, net of premiums, discounts, unearned income, deferred loan origination fees and costs, and the ALLL. Interest income on these loans is accrued based on the principal amount outstanding. Non-refundable loan origination fees, net of direct costs of originating or acquiring loans, as well as purchase premiums and discounts, are deferred and recognized as adjustments to yield over the contractual lives of the related loans using the level yield method. Direct Financing Leases Direct financing leases are carried at the aggregate of lease payments receivable and estimated residual value of the leased property, if applicable, less unearned income. Interest income on direct financing leases is recognized over the term of the leases to achieve a constant periodic rate of return on the outstanding investment. Initial direct costs are deferred and amortized over the lease term as a reduction to interest income using the effective interest method. ACI Loans ACI loans, all of which were acquired in the FSB Acquisition and the substantial majority of which are covered under the Single Family Shared-Loss Agreement, are those for which, at acquisition, management determined it probable that the Company would be unable to collect all contractual principal and interest payments due. These loans were recorded at estimated fair value at acquisition, measured as the present value of all cash flows expected to be received, discounted at an appropriately risk-adjusted discount rate. Initial cash flow expectations incorporated significant assumptions regarding prepayment rates, frequency of default and loss severity. The difference between total contractually required payments on ACI loans and the cash flows expected to be received represents non-accretable difference. The excess of all cash flows expected to be received over the Company's recorded investment in the loans represents accretable yield and is recognized as interest income on a level-yield basis over the expected life of the loans. The Company aggregated ACI 1-4 single family residential mortgage loans and home equity loans and lines of credit with similar risk characteristics into homogenous pools at acquisition. A composite interest rate and composite expectations of future cash flows are used in accounting for each pool. These loans were aggregated into pools based on the following characteristics: • delinquency status; • product type, in particular, amortizing as opposed to option ARMs; • loan-to-value ratio; and • borrower FICO score. Loans that do not have similar risk characteristics, primarily commercial and commercial real estate loans, are accounted for on an individual loan basis using interest rates and expectations of cash flows for each loan. The Company is required to develop reasonable expectations about the timing and amount of cash flows to be collected related to ACI loans and to continue to update those estimates over the lives of the loans. Expected cash flows from ACI loans are updated quarterly. If it is probable that the Company will be unable to collect all the cash flows expected from a loan or pool at acquisition plus additional cash flows expected to be collected arising from changes in estimates after acquisition, the loan or pool is considered impaired and a valuation allowance is established by a charge to the provision for loan losses. If there is an increase in expected cash flows from a loan or pool, the Company first reduces any valuation allowance previously established by the amount of the increase in the present value of expected cash flows, and then recalculates the amount of accretable yield for that loan or pool. The adjustment of accretable yield due to an increase in expected cash flows, as well as changes in expected cash flows due to changes in interest rate indices and changes in prepayment assumptions is accounted for prospectively as a change in yield. Additional cash flows expected to be collected are transferred from non-accretable difference to accretable yield and the amount of periodic accretion is adjusted accordingly over the remaining life of the loan or pool. The Company may resolve an ACI loan either through a sale of the loan, by working with the customer and obtaining partial or full repayment, by short sale of the collateral, or by foreclosure. When a loan accounted for in a pool is resolved, it is removed from the pool at its allocated carrying amount. In the event of a sale of the loan, the Company recognizes a gain or loss on sale based on the difference between the sales proceeds and the carrying amount of the loan. For loans resolved through pre-payment or short sale of the collateral, the Company recognizes the difference between the amount of the payment received and the carrying amount of the loan in the income statement line item "Income from resolution of covered assets, net". For loans resolved through foreclosure, the difference between the fair value of the collateral obtained through foreclosure less estimated cost to sell and the carrying amount of the loan is recognized in the income statement line item "Income from resolution of covered assets, net". Any remaining accretable discount related to loans not accounted for in pools that are resolved by full or partial pre-payment, short sale or foreclosure is recognized in interest income at the time of resolution, to the extent collected. Payments received earlier than expected or in excess of expected cash flows from sales or other resolutions may result in the carrying value of a pool being reduced to zero even though outstanding contractual balances and expected cash flows remain related to loans in the pool. Once the carrying value of a pool is reduced to zero, any future proceeds, which may include cash or real estate acquired in foreclosure, from the remaining loans, representing further realization of accretable yield, are recognized as interest income upon receipt. Covered Non-ACI Loans Loans acquired in the FSB Acquisition without evidence of deterioration in credit quality since origination were initially recorded at estimated fair value on the acquisition date. Non-ACI 1-4 single family residential mortgage loans and home equity loans and lines of credit with similar risk characteristics were aggregated into pools for accounting purposes at acquisition. Non-ACI loans are carried at the principal amount outstanding, adjusted for unamortized acquisition date fair value adjustments and the ALLL. Interest income is accrued based on the UPB and, with the exception of home equity loans and lines of credit, acquisition date fair value adjustments are amortized using the level-yield method over the expected lives of the related loans. For non-ACI 1-4 family residential mortgage loans accounted for in pools, prepayment estimates are used in determining the periodic amortization of acquisition date fair value adjustments. Acquisition date fair value adjustments related to revolving home equity loans and lines of credit are amortized on a straight-line basis. Non-accrual Loans Commercial loans, other than ACI loans, are placed on non-accrual status when (i) management has determined that full repayment of all contractual principal and interest is in doubt, or (ii) the loan is past due 90 days or more as to principal or interest unless the loan is well secured and in the process of collection. Given continued unstable conditions in the taxi industry, continued declines in ridership, and the relatively long amortization periods for most of these loans, there exists an increasing level of uncertainty with respect to the Company's ability to collect all contractual principal and interest on taxi medallion loans. Therefore, all taxi medallion loans have been placed on non-accrual status. Residential and consumer loans, other than ACI loans, are generally placed on non-accrual status when 90 days of interest is due and unpaid. When a loan is placed on non-accrual status, uncollected interest accrued is reversed and charged to interest income. Payments received on nonaccrual commercial loans are applied as a reduction of principal. Interest payments are recognized as income on a cash basis on nonaccrual residential loans. Commercial loans are returned to accrual status only after all past due principal and interest has been collected and full repayment of remaining contractual principal and interest is reasonably assured. Residential and consumer loans are returned to accrual status when there is no longer 90 days of interest due and unpaid. Past due status of loans is determined based on the contractual next payment due date. Loans less than 30 days past due are reported as current. Contractually delinquent ACI loans are not classified as non-accrual as long as discount continues to be accreted on the loans or pools. Impaired Loans Loans, other than ACI loans, are considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due, according to the contractual terms of the loan agreements. Commercial relationships with committed balances greater than or equal to $1.0 million that have internal risk ratings of substandard or doubtful and are on non-accrual status, as well as loans that have been modified in TDRs, are individually evaluated for impairment. Other commercial relationships on non-accrual status with committed balances under $1.0 million may also be evaluated individually for impairment at management's discretion. All loans secured by taxi medallions are individually evaluated for impairment. The likelihood of loss related to loans assigned internal risk ratings of substandard or doubtful is considered elevated due to their identified credit weaknesses. Factors considered by management in evaluating impairment include payment status, financial condition of the borrower, collateral value, and other factors impacting the probability of collecting scheduled principal and interest payments when due. An ACI pool or loan is considered to be impaired when it is probable that the Company will be unable to collect all the cash flows expected at acquisition, plus additional cash flows expected to be collected arising from changes in estimates after acquisition. 1-4 single family residential and home equity ACI loans accounted for in pools are evaluated collectively for impairment on a pool by pool basis based on expected pool cash flows. Commercial ACI loans are individually evaluated for impairment based on expected cash flows from the individual loans. Discount continues to be accreted on ACI loans or pools as long as there are expected future cash flows in excess of the current carrying amount of the loans or pools. Troubled Debt Restructurings In certain situations due to economic or legal reasons related to a borrower's financial difficulties, the Company may grant a concession to the borrower for other than an insignificant period of time that it would not otherwise consider. At that time, except for ACI loans accounted for in pools, the related loan is classified as a TDR and considered impaired. The concessions granted may include rate reductions, principal forgiveness, payment forbearance, extensions of maturity at rates of interest below that commensurate with the risk profile of the loans, modification of payment terms and other actions intended to minimize economic loss. A TDR is generally placed on non-accrual status at the time of the modification unless the borrower was performing prior to the restructuring. Modified ACI loans accounted for in pools are not accounted for as TDRs, are not separated from the pools and are not classified as impaired loans. Allowance for Loan and Lease Losses The ALLL represents the amount considered adequate by management to absorb probable losses inherent in the loan portfolio at the balance sheet date. The ALLL consists of both specific and general components. The ALLL is established as losses are estimated to have occurred through a provision charged to earnings. Individual loans are charged off against the ALLL when management determines them to be uncollectible. An assessment of collateral value is made at no later than 120 days delinquency for non-covered open- and closed-end loans secured by residential real estate; any outstanding loan balance in excess of fair value less cost to sell is charged off at no later than 180 days delinquency. Additionally, any outstanding balance in excess of fair value of collateral less cost to sell is charged off (i) within 60 days of receipt of notification of filing from the bankruptcy court, (ii) within 60 days of determination of loss if all borrowers are deceased or (iii) within 90 days of discovery of fraudulent activity. Covered non-ACI loans secured by residential real estate are generally charged off at final resolution which is consistent with the terms of the Single Family Shared-Loss Agreement. Consumer loans are typically charged off at 120 days delinquency. Commercial loans are charged off when management deems them to be uncollectible. Subsequent recoveries are credited to the ALLL. Non-covered Loans The non-covered residential and home equity portfolio segments have not yet developed an observable loss trend. Due to several factors, there is a lack of similarity between the risk characteristics of non-covered loans and covered loans in the residential and home equity portfolios. Therefore, management does not believe it is appropriate to use the historical performance of the covered residential loans as a basis for calculating the ALLL applicable to the non-covered loans. The ALLL for non-covered 1-4 single family residential loans is based on average annual loss rates on prime residential mortgage securitizations issued between 2003 and 2008. Loans included in these securitizations have credit characteristics, such as LTV and FICO scores, considered by management to be comparable to characteristics of loans in the non-covered 1-4 single family residential portfolio. The ALLL for non-covered home equity and other consumer loans is based on peer group average historical loss rates. The credit quality of loans in the residential portfolio segment may be impacted by fluctuations in home values, unemployment, general economic conditions, borrowers' financial circumstances and fluctuations in interest rates. The credit quality of commercial loans is impacted by general and industry specific economic conditions and other factors that may influence debt service coverage generated by the borrowers' businesses as well as fluctuations in the value of real estate and other collateral. For loans evaluated individually for impairment and determined to be impaired, a specific allowance is established based on the present value of expected cash flows discounted at the loan's effective interest rate, the estimated fair value of the loan, or for collateral dependent loans, the estimated fair value of collateral less costs to sell. Commercial loans, other than ACI commercial loans, not individually determined to be impaired are grouped based on common risk characteristics. Quantitative loss factors for pass rated commercial loans in portfolio segments that have not yet developed an observable loss trend are based primarily on peer group average historical loss rates and the Bank's internal credit risk rating system. Quantitative loss factors for the Bridge portfolios, small business loans and mortgage warehouse loans are based on the Company's average historical net charge-off rates. The quantitative loss factor applied to the non-guaranteed portion of SBA loans is based on average historical charge-off rates published by the SBA. The quantitative loss factor for municipal loans and direct finance leases is based on the portfolio's external ratings and Moody's historical transition matrix. Quantitative loss rates are generally based on a four -quarter loss emergence period and a 16 -quarter loss experience period; for municipal loans and leases, a 12 -quarter loss emergence period is used. The source of quantitative loss factors for the Bridge portfolios, municipal loans and leases, SBA loans, and mortgage warehouse loans was revised in 2017, with no material impact to the ALLL. Where applicable, the peer group used to calculate average annual historical net charge-off rates used in estimating the Bank's general reserves is a group of 27 banks made up of the banks included in the OCC Midsize Bank Group and two additional banks in the New York region that management believes to be comparable based on size and nature of lending operations. The quantitative loss factor for loans rated special mention is based on average annual probability of default and implied severity, derived from internal and external data. Loss factors for substandard and doubtful loans that are not individually evaluated for impairment are determined by using default frequency and severity information applied at the loan level. Estimated default frequencies and severities are based on available industry data. Qualitative adjustments are made to the ALLL when, based on management's judgment and experience, there are internal or external factors impacting incurred losses not taken into account by the quantitative calculations. Management has categorized potential qualitative adjustments into the following categories: • Portfolio performance trends, including trends in and the levels of delinquencies, non-performing loans and classified loans; • Changes in the nature of the portfolio and terms of the loans, specifically including the volume and nature of policy and procedural exceptions; • Portfolio growth trends; • Changes in lending policies and procedures, including credit and underwriting guidelines; • Economic factors, including unemployment rates and GDP growth rates; • Changes in the value of underlying collateral; • Quality of risk ratings, as evaluated by our independent credit review function; • Credit concentrations; • Changes in and experience levels of credit administration management and staff; and • Other factors identified by management that may impact the level of losses inherent in the portfolio, including but not limited to competition, legal and regulatory requirements and unusual events. Covered Non-ACI Loans Calculated loss frequency and severity percentages are applied to the UPB of non-ACI 1-4 single family residential mortgages and home equity loans and lines of credit to calculate the ALLL. Based on an analysis of historical portfolio performance, OREO and short sale data, and other internal and external factors, management has concluded that historical performance by portfolio class is the best indicator of incurred loss for the non-ACI 1-4 single family residential and home equity portfolio classes. For each of these portfolio classes, a quarterly roll rate matrix is used to measure the rate at which loans move from one delinquency bucket to the next during a given quarter. An average 16-quarter roll rate matrix is used to estimate the amount within each delinquency bucket expected to roll to 120 + days delinquent within a four quarter loss emergence period. Loss severity given default is estimated based on internal data about short sales and OREO sales. The ALLL calculation incorporates a 100% loss severity assumption for home equity loans and lines of credit projected to roll to 120 days delinquency. Substantially all non-ACI home equity loans and lines of credit were sold in the fourth quarter of 2017. ACI Loans A specific valuation allowance related to an ACI loan or pool is established when quarterly evaluations of expected cash flows indicate it is probable that the Company will be unable to collect all of the cash flows expected at acquisition plus any additional cash flows expected to be collected arising from changes in estimate after acquisition. The amount of any necessary valuation allowance is measu

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share The computation of basic and diluted earnings per common share is presented below for the years ended December 31, 2017 , 2016 and 2015 (in thousands, except share and per share data): c 2017 2016 2015 Basic earnings per common share: Numerator: Net income $ 614,273 $ 225,741 $ 251,660 Distributed and undistributed earnings allocated to participating securities (23,250 ) (8,760 ) (9,742 ) Income allocated to common stockholders for basic earnings per common share $ 591,023 $ 216,981 $ 241,918 Denominator: Weighted average common shares outstanding 106,574,448 104,097,182 103,187,530 Less average unvested stock awards (1,104,035 ) (1,157,378 ) (1,128,416 ) Weighted average shares for basic earnings per common share 105,470,413 102,939,804 102,059,114 Basic earnings per common share $ 5.60 $ 2.11 $ 2.37 Diluted earnings per common share: Numerator: Income allocated to common stockholders for basic earnings per common share $ 591,023 $ 216,981 $ 241,918 Adjustment for earnings reallocated from participating securities (263 ) 62 54 Income used in calculating diluted earnings per common share $ 590,760 $ 217,043 $ 241,972 Denominator: Weighted average shares for basic earnings per common share 105,470,413 102,939,804 102,059,114 Dilutive effect of stock options 387,074 716,366 913,036 Weighted average shares for diluted earnings per common share 105,857,487 103,656,170 102,972,150 Diluted earnings per common share $ 5.58 $ 2.09 $ 2.35 Included in participating securities above are unvested shares and 3,023,314 dividend equivalent rights outstanding at December 31, 2017 that were issued in conjunction with the IPO of the Company's common stock. These dividend equivalent rights expire in 2021 and participate in dividends on a one-for-one basis. The following potentially dilutive securities were outstanding at December 31, 2017 , 2016 , and 2015 but excluded from the calculation of diluted earnings per common share for the periods indicated because their inclusion would have been anti-dilutive: 2017 2016 2015 Unvested shares and share units 1,431,761 1,303,208 1,040,385 Stock options and warrants 1,850,279 1,850,279 1,851,376

Acquisition Activity

Acquisition Activity	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisition Activity	Acquisition Activity On May 1, 2015, BankUnited completed the acquisition of SBF from CertusHoldings, Inc. in an asset purchase transaction for a cash purchase price of $278 million . SBF's primary business activity is to originate loans under programs administered by the SBA. The SBF acquisition has allowed BankUnited to expand its small business lending platform on a national basis. BankUnited acquired the SBF loan portfolio, as well as substantially all of SBF's operating assets, and assumed certain of its operating liabilities. The acquisition of SBF was determined to be a business combination and was accounted for using the acquisition method of accounting; accordingly, the assets acquired and liabilities assumed were recorded at their estimated fair values at the acquisition date. The following table summarizes the estimated fair values of assets acquired and liabilities assumed (in thousands): Assets: Loans held for investment $ 173,809 Loans held for sale 82,143 Servicing rights 10,418 Other assets 4,397 Total assets 270,767 Total liabilities 3,620 Estimated fair value of net assets acquired 267,147 Consideration issued 277,553 Excess of consideration issued over fair value of net assets acquired $ 10,406

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities Investment securities available for sale consisted of the following at December 31, 2017 and 2016 (in thousands): 2017 Amortized Cost Gross Unrealized Fair Value Gains Losses U.S. Treasury securities $ 24,981 $ — $ (28 ) $ 24,953 U.S. Government agency and sponsored enterprise residential MBS 2,043,373 16,094 (1,440 ) 2,058,027 U.S. Government agency and sponsored enterprise commercial MBS 233,522 1,330 (344 ) 234,508 Private label residential MBS and CMOs 613,732 16,473 (1,958 ) 628,247 Private label commercial MBS 1,033,022 13,651 (258 ) 1,046,415 Single family rental real estate-backed securities 559,741 3,823 (858 ) 562,706 Collateralized loan obligations 720,429 3,252 — 723,681 Non-mortgage asset-backed securities 119,939 1,808 — 121,747 Preferred stocks 59,912 3,631 — 63,543 State and municipal obligations 640,511 17,606 (914 ) 657,203 SBA securities 534,534 16,208 (60 ) 550,682 Other debt securities 4,090 5,030 — 9,120 $ 6,587,786 $ 98,906 $ (5,860 ) $ 6,680,832 2016 Amortized Cost Gross Unrealized Fair Value Gains Losses U.S. Treasury securities $ 4,999 $ 6 $ — $ 5,005 U.S. Government agency and sponsored enterprise residential MBS 1,513,028 15,922 (1,708 ) 1,527,242 U.S. Government agency and sponsored enterprise commercial MBS 126,754 670 (2,838 ) 124,586 Private label residential MBS and CMOs 334,167 42,939 (2,008 ) 375,098 Private label commercial MBS 1,180,386 9,623 (2,385 ) 1,187,624 Single family rental real estate-backed securities 858,339 4,748 (1,836 ) 861,251 Collateralized loan obligations 487,678 868 (1,250 ) 487,296 Non-mortgage asset-backed securities 187,660 2,002 (2,926 ) 186,736 Preferred stocks 76,180 12,027 (4 ) 88,203 State and municipal obligations 705,884 3,711 (11,049 ) 698,546 SBA securities 517,129 7,198 (421 ) 523,906 Other debt securities 3,999 4,092 — 8,091 $ 5,996,203 $ 103,806 $ (26,425 ) $ 6,073,584 Investment securities held to maturity at December 31, 2017 and 2016 consisted of one State of Israel bond with a carrying value of $10 million . Fair value approximated carrying value at December 31, 2017 and 2016 . The bond matures in 2024. At December 31, 2017 , contractual maturities of investment securities available for sale, adjusted for anticipated prepayments of mortgage-backed and other pass-through securities, were as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 663,592 $ 674,291 Due after one year through five years 3,196,717 3,232,157 Due after five years through ten years 2,229,852 2,264,131 Due after ten years 437,713 446,710 Preferred stocks with no stated maturity 59,912 63,543 $ 6,587,786 $ 6,680,832 Based on the Company’s assumptions, the estimated weighted average life of the investment portfolio as of December 31, 2017 was 4.9 years. The effective duration of the investment portfolio as of December 31, 2017 was 1.7 years. The model results are based on assumptions that may differ from actual results. The carrying value of securities pledged as collateral for FHLB advances, public deposits, interest rate swaps and to secure borrowing capacity at the FRB totaled $2.6 billion and $1.8 billion at December 31, 2017 and 2016 , respectively. The following table provides information about gains and losses on investment securities available for sale for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 2016 2015 Proceeds from sale of investment securities available for sale $ 1,287,591 $ 1,127,983 $ 1,114,020 Gross realized gains $ 37,530 $ 14,924 $ 8,955 Gross realized losses (4,064 ) — (475 ) Net realized gain 33,466 14,924 8,480 OTTI — (463 ) — Gain on investment securities available for sale, net $ 33,466 $ 14,461 $ 8,480 During the year ended December 31, 2016, OTTI was recognized on two positions in one private label commercial MBS. These positions were sold at a loss before the end of 2016. The following tables present the aggregate fair value and the aggregate amount by which amortized cost exceeded fair value for investment securities in unrealized loss positions, aggregated by investment category and length of time that individual securities had been in continuous unrealized loss positions at December 31, 2017 and 2016 (in thousands): 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Treasury securities $ 24,953 $ (28 ) $ — $ — $ 24,953 $ (28 ) U.S. Government agency and sponsored enterprise residential MBS 471,120 (1,141 ) 13,028 (299 ) 484,148 (1,440 ) U.S. Government agency and sponsored enterprise commercial MBS 26,265 (344 ) — — 26,265 (344 ) Private label residential MBS and CMOs 330,068 (1,858 ) 5,083 (100 ) 335,151 (1,958 ) Private label commercial MBS 81,322 (258 ) — — 81,322 (258 ) Single family rental real estate-backed securities 94,750 (858 ) — — 94,750 (858 ) State and municipal obligations 30,715 (49 ) 60,982 (865 ) 91,697 (914 ) SBA securities 21,300 (10 ) 15,427 (50 ) 36,727 (60 ) $ 1,080,493 $ (4,546 ) $ 94,520 $ (1,314 ) $ 1,175,013 $ (5,860 ) 2016 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Government agency and sponsored enterprise residential MBS $ 191,463 $ (628 ) $ 112,391 $ (1,080 ) $ 303,854 $ (1,708 ) U.S. Government agency and sponsored enterprise commercial MBS 89,437 (2,838 ) — — 89,437 (2,838 ) Private label residential MBS and CMOs 122,142 (1,680 ) 8,074 (328 ) 130,216 (2,008 ) Private label commercial MBS 169,535 (2,370 ) 24,985 (15 ) 194,520 (2,385 ) Single family rental real estate-backed securities 139,867 (842 ) 176,057 (994 ) 315,924 (1,836 ) Collateralized loan obligations 69,598 (402 ) 173,983 (848 ) 243,581 (1,250 ) Non-mortgage asset-backed securities 139,477 (2,926 ) — — 139,477 (2,926 ) Preferred stocks 10,087 (4 ) — — 10,087 (4 ) State and municipal obligations 448,180 (11,049 ) — — 448,180 (11,049 ) SBA securities 4,204 (13 ) 20,076 (408 ) 24,280 (421 ) $ 1,383,990 $ (22,752 ) $ 515,566 $ (3,673 ) $ 1,899,556 $ (26,425 ) The Company monitors its investment securities available for sale for OTTI on an individual security basis. No securities were determined to be other-than-temporarily impaired during the years ended December 31, 2017 and 2015 . As discussed above, OTTI was recognized on two positions in one private label commercial MBS during the year ended December 31, 2016 . The Company does not intend to sell securities that are in significant unrealized loss positions at December 31, 2017 and it is not more likely than not that the Company will be required to sell these securities before recovery of the amortized cost basis, which may be at maturity. At December 31, 2017 , 71 securities were in unrealized loss positions. The amount of impairment related to 28 of these securities was considered insignificant, totaling approximately $277 thousand and no further analysis with respect to these securities was considered necessary. The basis for concluding that impairment of the remaining securities was not other-than-temporary is further described below: U.S. Treasury securities At December 31, 2017 , one U.S. Treasury security was in unrealized loss position. The amount of impairment is less than 1% of amortized cost. The timely payment of principal and interest on this security is explicitly guaranteed by the U.S. Government. Given the limited severity of impairment and the expectation of timely payments of principal and interest, the impairment is considered to be temporary. U.S. Government agency and sponsored enterprise residential and commercial MBS At December 31, 2017 , eleven U.S. Government agency and sponsored enterprise residential MBS and three U.S. Government agency and sponsored enterprise commercial MBS were in unrealized loss positions. For eight fixed rate securities, the amount of impairment for each of the securities was less than 3% of amortized cost and was primarily attributable to an increase in medium and long-term market interest rates subsequent to the date of acquisition. For the remaining six variable rate securities, the amount of impairment was less than 1% of amortized cost. The timely payment of principal and interest on these securities is explicitly or implicitly guaranteed by the U.S. Government. Given the limited severity of impairment and the expectation of timely payment of principal and interest, the impairments were considered to be temporary. Private label residential MBS and CMOs At December 31, 2017 , twelve private label residential MBS and CMOs were in unrealized loss positions, primarily as a result of an increase in medium and long-term market interest rates subsequent to acquisition. The amount of impairment of each of the individual securities was 2% or less of amortized cost. These securities were assessed for OTTI using credit and prepayment behavioral models that incorporate CUSIP level constant default rates, voluntary prepayment rates and loss severity and delinquency assumptions. The results of these assessments were not indicative of credit losses related to any of these securities as of December 31, 2017 . Given the limited severity of impairment and the expectation of timely recovery of outstanding principal, the impairments were considered to be temporary. Private label commercial MBS At December 31, 2017 , three private label commercial MBS were in unrealized loss positions. The amount of impairment of each of the individual securities was less than 1% of amortized cost. These securities were assessed for OTTI using credit and prepayment behavioral models incorporating assumptions consistent with the collateral characteristics of each security. The results of this analysis were not indicative of expected credit losses. Given the limited severity of impairment and the expectation of timely recovery of outstanding principal, the impairments were considered to be temporary. Single family rental real estate-backed securities At December 31, 2017 , six single family rental real estate-backed securities were in unrealized loss positions. The unrealized losses were primarily due to increases in market interest rates since the purchase of the securities. The amount of impairment of each of the individual securities was less than 2% of amortized cost. Management's analysis of the credit characteristics, including loan-to-value and debt service coverage ratios, and levels of subordination for each of the securities is not indicative of projected credit losses. Given the limited severity of impairment and the absence of projected credit losses, the impairments were considered to be temporary. State and municipal obligations At December 31, 2017 , six state and municipal obligations were in unrealized loss positions. The amount of impairment of each of the individual securities was less than 3% of amortized cost. All of the securities are rated investment grade by nationally recognized statistical ratings organizations. Management's evaluation of these securities for OTTI also encompassed the review of credit scores and analysis provided by a third party firm specializing in the analysis and credit review of municipal securities. Given the absence of expected credit losses and management's ability and intent to hold the securities until recovery, the impairments were considered to be temporary. SBA Securities At December 31, 2017 , one SBA security was in an unrealized loss position. The amount of impairment was less than 1% of amortized cost. This security was purchased at a premium and the impairment was attributable primarily to increased prepayment speeds. The timely payment of principal and interest on this security is guaranteed by this U.S. Government agency. Given the limited severity of impairment and the expectation of timely payment of principal and interest, the impairment was considered to be temporary.

Loans and Allowance for Loan an

Loans and Allowance for Loan and Lease Losses	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans and Allowance for Loan and Lease Losses	Loans and Allowance for Loan and Lease Losses At December 31, 2017 and 2016 , loans consisted of the following (dollars in thousands): 2017 Covered Loans Percent of Total Non-Covered Loans ACI Non-ACI Total Residential and other consumer: 1-4 single family residential $ 4,116,814 $ 479,068 $ 26,837 $ 4,622,719 21.6 % Home equity loans and lines of credit 1,654 — 361 2,015 — % Other consumer loans 20,512 — — 20,512 0.1 % 4,138,980 479,068 27,198 4,645,246 21.7 % Commercial: Multi-family 3,215,697 — — 3,215,697 15.0 % Non-owner occupied commercial real estate 4,485,276 — — 4,485,276 21.0 % Construction and land 310,999 — — 310,999 1.5 % Owner occupied commercial real estate 2,014,908 — — 2,014,908 9.4 % Commercial and industrial 4,145,785 — — 4,145,785 19.4 % Commercial lending subsidiaries 2,553,576 — — 2,553,576 12.0 % 16,726,241 — — 16,726,241 78.3 % Total loans 20,865,221 479,068 27,198 21,371,487 100.0 % Premiums, discounts and deferred fees and costs, net 48,165 — (3,148 ) 45,017 Loans including premiums, discounts and deferred fees and costs 20,913,386 479,068 24,050 21,416,504 Allowance for loan and lease losses (144,537 ) — (258 ) (144,795 ) Loans, net $ 20,768,849 $ 479,068 $ 23,792 $ 21,271,709 2016 Covered Loans Percent of Total Non-Covered Loans ACI Non-ACI Total Residential and other consumer: 1-4 single family residential $ 3,422,425 $ 532,348 $ 36,675 $ 3,991,448 20.6 % Home equity loans and lines of credit 1,120 3,894 47,629 52,643 0.3 % Other consumer loans 24,365 — — 24,365 0.1 % 3,447,910 536,242 84,304 4,068,456 21.0 % Commercial: Multi-family 3,824,973 — — 3,824,973 19.8 % Non-owner occupied commercial real estate 3,739,235 — — 3,739,235 19.3 % Construction and land 311,436 — — 311,436 1.6 % Owner occupied commercial real estate 1,736,858 — — 1,736,858 9.0 % Commercial and industrial 3,391,614 — — 3,391,614 17.5 % Commercial lending subsidiaries 2,280,685 — — 2,280,685 11.8 % 15,284,801 — — 15,284,801 79.0 % Total loans 18,732,711 536,242 84,304 19,353,257 100.0 % Premiums, discounts and deferred fees and costs, net 48,641 — (6,504 ) 42,137 Loans including premiums, discounts and deferred fees and costs 18,781,352 536,242 77,800 19,395,394 Allowance for loan and lease losses (150,853 ) — (2,100 ) (152,953 ) Loans, net $ 18,630,499 $ 536,242 $ 75,700 $ 19,242,441 Included in non-covered loans above are $34 million and $47 million at December 31, 2017 and 2016 , respectively, of ACI commercial loans acquired in the FSB Acquisition. Through two subsidiaries, the Bank provides commercial and municipal equipment and franchise financing utilizing both loan and lease structures. At December 31, 2017 and 2016 , the commercial lending subsidiaries portfolio included a net investment in direct financing leases of $738 million and $643 million , respectively. The following table presents the components of the investment in direct financing leases as of December 31, 2017 and 2016 (in thousands): 2017 2016 Total minimum lease payments to be received $ 792,064 $ 689,631 Estimated unguaranteed residual value of leased assets 17,872 3,704 Gross investment in direct financing leases 809,936 693,335 Unearned income (76,900 ) (55,891 ) Initial direct costs 5,184 5,287 $ 738,220 $ 642,731 As of December 31, 2017 , future minimum lease payments to be received under direct financing leases were as follows (in thousands): Years Ending December 31: 2018 $ 189,017 2019 158,846 2020 121,930 2021 74,536 2022 49,781 Thereafter 197,954 $ 792,064 During both of the years ended December 31, 2017 and 2016 , the Company purchased 1-4 single family residential loans totaling $1.3 billion . At December 31, 2017 , the Company had pledged real estate loans with UPB of approximately $10.5 billion and recorded investment of approximately $10.0 billion as security for FHLB advances. At December 31, 2017 and 2016 , the UPB of ACI loans was $1.1 billion and $1.5 billion , respectively. The accretable yield on ACI loans represents the amount by which undiscounted expected future cash flows exceed recorded investment. Changes in the accretable yield on ACI loans for the years ended December 31, 2017 , 2016 , and 2015 were as follows (in thousands): Balance at December 31, 2014 $ 1,005,312 Reclassifications from non-accretable difference 192,291 Accretion (295,038 ) Balance at December 31, 2015 902,565 Reclassifications from non-accretable difference 76,751 Accretion (303,931 ) Balance at December 31, 2016 675,385 Reclassifications from non-accretable difference 81,501 Accretion (301,827 ) Balance at December 31, 2017 $ 455,059 Reclassifications from non-accretable difference in the table above for the year ended December 31, 2017 included $16.3 million of remaining accretable yield included in the determination of the recorded investment in the pool of ACI home equity loans and lines of credit, which was sold in its entirety in the fourth quarter of 2017. Covered loan sales During the years ended December 31, 2017 , 2016 and 2015 , the Company sold covered residential loans to third parties on a non-recourse basis. The following table summarizes the impact of these transactions (in thousands): 2017 2016 2015 UPB of loans sold $ 203,970 $ 241,348 $ 249,038 Cash proceeds, net of transaction costs $ 169,828 $ 171,367 $ 207,425 Recorded investment in loans sold 152,422 185,837 172,496 Gain (loss) on sale of covered loans, net $ 17,406 $ (14,470 ) $ 34,929 Gain (loss) on FDIC indemnification, net $ (1,523 ) $ 11,615 $ (28,051 ) Allowance for loan and lease losses Activity in the ALLL for the years ended December 31, 2017 , 2016 , and 2015 is summarized as follows (in thousands): 2017 Residential and Other Consumer Commercial Total Beginning balance $ 11,503 $ 141,450 $ 152,953 Provision for (recovery of) loan losses: Covered loans 1,418 (60 ) 1,358 Non-covered loans 1,034 66,355 67,389 Total provision 2,452 66,295 68,747 Charge-offs: Covered loans (3,327 ) — (3,327 ) Non-covered loans (1 ) (77,865 ) (77,866 ) Total charge-offs (3,328 ) (77,865 ) (81,193 ) Recoveries: Covered loans 67 60 127 Non-covered loans 26 4,135 4,161 Total recoveries 93 4,195 4,288 Ending balance $ 10,720 $ 134,075 $ 144,795 2016 Residential and Other Consumer Commercial Total Beginning balance $ 16,211 $ 109,617 $ 125,828 Provision for (recovery of) loan losses: Covered loans (1,632 ) (49 ) (1,681 ) Non-covered loans (1,814 ) 54,406 52,592 Total provision (3,446 ) 54,357 50,911 Charge-offs: Covered loans (1,216 ) — (1,216 ) Non-covered loans (152 ) (25,742 ) (25,894 ) Total charge-offs (1,368 ) (25,742 ) (27,110 ) Recoveries: Covered loans 80 49 129 Non-covered loans 26 3,169 3,195 Total recoveries 106 3,218 3,324 Ending balance $ 11,503 $ 141,450 $ 152,953 2015 Residential and Other Consumer Commercial Total Beginning balance $ 11,515 $ 84,027 $ 95,542 Provision for (recovery of) loan losses: Covered loans 2,317 (66 ) 2,251 Non-covered loans 3,988 38,072 42,060 Total provision 6,305 38,006 44,311 Charge-offs: Covered loans (1,680 ) — (1,680 ) Non-covered loans — (13,719 ) (13,719 ) Total charge-offs (1,680 ) (13,719 ) (15,399 ) Recoveries: Covered loans 39 66 105 Non-covered loans 32 1,237 1,269 Total recoveries 71 1,303 1,374 Ending balance $ 16,211 $ 109,617 $ 125,828 The following table presents information about the balance of the ALLL and related loans as of December 31, 2017 and 2016 (in thousands): 2017 2016 Residential and Other Consumer Commercial Total Residential and Other Consumer Commercial Total Allowance for loan and lease losses: Ending balance $ 10,720 $ 134,075 $ 144,795 $ 11,503 $ 141,450 $ 152,953 Covered loans: Ending balance $ 258 $ — $ 258 $ 2,100 $ — $ 2,100 Ending balance: non-ACI loans individually evaluated for impairment $ 118 $ — $ 118 $ 529 $ — $ 529 Ending balance: non-ACI loans collectively evaluated for impairment $ 140 $ — $ 140 $ 1,571 $ — $ 1,571 Ending balance: ACI loans $ — $ — $ — $ — $ — $ — Non-covered loans: Ending balance $ 10,462 $ 134,075 $ 144,537 $ 9,403 $ 141,450 $ 150,853 Ending balance: loans individually evaluated for impairment $ 63 $ 18,776 $ 18,839 $ 12 $ 19,229 $ 19,241 Ending balance: loans collectively evaluated for impairment $ 10,399 $ 115,299 $ 125,698 $ 9,391 $ 122,221 $ 131,612 Ending balance: ACI loans $ — $ — $ — $ — $ — $ — Loans: 0 Covered loans: Ending balance $ 503,118 $ — $ 503,118 $ 614,042 $ — $ 614,042 Ending balance: non-ACI loans individually evaluated for impairment $ 2,221 $ — $ 2,221 $ 12,396 $ — $ 12,396 Ending balance: non-ACI loans collectively evaluated for impairment $ 21,829 $ — $ 21,829 $ 65,404 $ — $ 65,404 Ending balance: ACI loans $ 479,068 $ — $ 479,068 $ 536,242 $ — $ 536,242 Non-covered loans: Ending balance $ 4,196,080 $ 16,717,306 $ 20,913,386 $ 3,495,775 $ 15,285,577 $ 18,781,352 Ending balance: loans, other than ACI loans, individually evaluated for impairment $ 1,234 $ 173,706 $ 174,940 $ 561 $ 176,932 $ 177,493 Ending balance: loans, other than ACI loans, collectively evaluated for impairment $ 4,194,846 $ 16,509,824 $ 20,704,670 $ 3,495,207 $ 15,061,707 $ 18,556,914 Ending balance: ACI loans $ — $ 33,776 $ 33,776 $ 7 $ 46,938 $ 46,945 Credit quality information The table below presents information about loans or ACI pools identified as impaired as of December 31, 2017 and 2016 (in thousands): 2017 2016 Recorded Investment UPB Related Specific Allowance Recorded Investment UPB Related Specific Allowance Non-covered loans: With no specific allowance recorded: 1-4 single family residential $ 120 $ 122 $ — $ — $ — $ — Non-owner occupied commercial real estate 10,922 10,838 — 510 512 — Construction and land 1,175 1,175 — 1,238 1,238 — Owner occupied commercial real estate 22,002 22,025 — 16,834 16,894 — Commercial and industrial Taxi medallion loans 13,560 13,559 — 18,107 18,107 — Other commercial and industrial 345 374 — 6,172 6,172 — Commercial lending subsidiaries — — — 10,620 10,510 — With a specific allowance recorded: 1-4 single family residential 1,114 1,090 63 561 546 12 Multi-family 23,173 23,175 1,732 — — — Owner occupied commercial real estate 3,075 3,079 2,960 491 513 263 Commercial and industrial Taxi medallion loans 92,507 92,508 12,214 73,131 73,147 5,948 Other commercial and industrial 3,626 3,624 1,540 29,452 29,463 9,168 Commercial lending subsidiaries 3,321 3,296 330 21,712 21,605 3,850 Total: Residential and other consumer $ 1,234 $ 1,212 $ 63 $ 561 $ 546 $ 12 Commercial 173,706 173,653 18,776 178,267 178,161 19,229 $ 174,940 $ 174,865 $ 18,839 $ 178,828 $ 178,707 $ 19,241 Covered loans: Non-ACI loans: With no specific allowance recorded: 1-4 single family residential $ 1,061 $ 1,203 $ — $ 1,169 $ 1,391 $ — Home equity loans and lines of credit — — — 2,255 2,286 — With a specific allowance recorded: 1-4 single family residential 1,160 1,314 118 1,272 1,514 181 Home equity loans and lines of credit — — — 7,700 7,804 348 $ 2,221 $ 2,517 $ 118 $ 12,396 $ 12,995 $ 529 Non-covered impaired loans include commercial real estate ACI loans modified in TDRs with a carrying value of $1.3 million as of December 31, 2016 . Interest income recognized on impaired loans and pools for the year ended December 31, 2017 was approximately $9.6 million . The interest income recognized on impaired loans for the years ended December 31, 2016 and 2015 was not material. The following table presents the average recorded investment in impaired loans for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 2016 2015 Non-Covered Loans Covered Non-ACI Loans Non-Covered Loans Covered Non-ACI Non-Covered Loans Covered Non-ACI Residential and other consumer: 1-4 single family residential $ 868 $ 2,345 $ 301 $ 3,067 $ 82 $ 3,655 Home equity loans and lines of credit — 8,403 — 9,225 4,830 868 $ 10,748 301 $ 12,292 82 $ 8,485 Commercial: Multi-family 4,259 — 291 Non-owner occupied commercial real estate 5,537 710 1,001 Construction and land 2,789 797 — Owner occupied commercial real estate 19,882 14,645 5,117 Commercial and industrial Taxi medallion loans 108,977 45,012 — Other commercial and industrial 38,275 40,443 35,976 Commercial lending subsidiaries 22,865 15,052 14,835 202,584 116,659 57,220 $ 203,452 $ 116,960 $ 57,302 In addition to the above, a pool of ACI home equity loans and lines of credit was impaired during 2017. All of the loans from this pool were sold in the fourth quarter of 2017. The average balance of impaired ACI home equity loans and lines of credit for the year ended December 31, 2017 was $3.9 million . The following table presents the recorded investment in loans on non-accrual status as of December 31, 2017 and 2016 (in thousands): 2017 2016 Non-Covered Loans Covered Non-Covered Loans Covered Non-ACI Loans Residential and other consumer: 1-4 single family residential $ 9,705 $ 1,010 $ 566 $ 918 Home equity loans and lines of credit — 331 — 2,283 Other consumer loans 821 — 2 — 10,526 $ 1,341 568 $ 3,201 Commercial: Non-owner occupied commercial real estate 12,716 559 Construction and land 1,175 1,238 Owner occupied commercial real estate 29,020 19,439 Commercial and industrial Taxi medallion loans 106,067 60,660 Other commercial and industrial 7,049 16,036 Commercial lending subsidiaries 3,512 32,645 159,539 130,577 $ 170,065 $ 131,145 Non-covered loans contractually delinquent by 90 days or more and still accruing totaled $1.9 million and $1.6 million at December 31, 2017 and 2016 , respectively. The amount of additional interest income that would have been recognized on non-accrual loans had they performed in accordance with their contractual terms was approximately $4.1 million and $3.5 million for the years ended December 31, 2017 and 2016 , respectively. Management considers delinquency status to be the most meaningful indicator of the credit quality of 1-4 single family residential, home equity and consumer loans. Delinquency statistics are updated at least monthly. See "Aging of loans" below for more information on the delinquency status of loans. Original LTV and original FICO score are also important indicators of credit quality for the non-covered 1-4 single family residential portfolio. Internal risk ratings are considered the most meaningful indicator of credit quality for commercial loans. Internal risk ratings are a key factor in identifying loans that are individually evaluated for impairment and impact management’s estimates of loss factors used in determining the amount of the ALLL. Internal risk ratings are updated on a continuous basis. Generally, relationships with balances in excess of defined thresholds, ranging from $1 million to $3 million , are re-evaluated at least annually and more frequently if circumstances indicate that a change in risk rating may be warranted. Loans exhibiting potential credit weaknesses that deserve management’s close attention and that if left uncorrected may result in deterioration of the repayment capacity of the borrower are categorized as special mention. Loans with well-defined credit weaknesses, including payment defaults, declining collateral values, frequent overdrafts, operating losses, increasing balance sheet leverage, inadequate cash flow, project cost overruns, unreasonable construction delays, past due real estate taxes or exhausted interest reserves, are assigned an internal risk rating of substandard. A loan with a weakness so severe that collection in full is highly questionable or improbable, but because of certain reasonably specific pending factors has not been charged off, will be assigned an internal risk rating of doubtful. The following tables summarize key indicators of credit quality for the Company's loans as of December 31, 2017 and 2016 . Amounts include premiums, discounts and deferred fees and costs (in thousands): 1-4 Single Family Residential credit exposure for non-covered loans, based on original LTV and FICO score: 2017 FICO LTV 720 or less 721 - 740 741 - 760 761 or greater Total 60% or less $ 92,316 $ 117,319 $ 185,193 $ 815,828 $ 1,210,656 60% - 70% 101,158 103,506 147,592 590,693 942,949 70% - 80% 149,958 183,376 324,887 1,139,969 1,798,190 More than 80% 33,776 32,563 30,404 125,415 222,158 $ 377,208 $ 436,764 $ 688,076 $ 2,671,905 $ 4,173,953 2016 FICO LTV 720 or less 721 - 740 741 - 760 761 or greater Total 60% or less $ 87,035 $ 113,401 $ 163,668 $ 751,291 $ 1,115,395 60% - 70% 80,694 94,592 124,180 523,970 823,436 70% - 80% 110,509 148,211 276,425 907,450 1,442,595 More than 80% 22,115 9,058 15,470 42,280 88,923 $ 300,353 $ 365,262 $ 579,743 $ 2,224,991 $ 3,470,349 Commercial credit exposure, based on internal risk rating: 2017 Commercial and Industrial Multi-Family Non-Owner Occupied Commercial Real Estate Construction Owner Occupied Commercial Real Estate Taxi Medallion Loans Other Commercial and Industrial Commercial Lending Subsidiaries Total Pass $ 3,124,819 $ 4,360,827 $ 305,043 $ 1,954,464 $ — $ 3,965,241 $ 2,478,998 $ 16,189,392 Special mention 34,837 33,094 — 22,161 — 37,591 55,551 183,234 Substandard 59,297 80,880 5,441 33,145 104,682 27,010 27,950 338,405 Doubtful — — — 2,972 1,385 1,918 — 6,275 $ 3,218,953 $ 4,474,801 $ 310,484 $ 2,012,742 $ 106,067 $ 4,031,760 $ 2,562,499 $ 16,717,306 2016 Commercial and Industrial Multi-Family Non-Owner Occupied Commercial Real Estate Construction and Land Owner Occupied Commercial Real Estate Taxi Medallion Loans Other Commercial and Industrial Commercial Lending Subsidiaries Total Pass $ 3,811,822 $ 3,694,931 $ 309,675 $ 1,672,199 $ 40,460 $ 3,112,590 $ 2,255,444 $ 14,897,121 Special mention 12,000 7,942 — 33,274 — 19,009 — 72,225 Substandard 5,852 28,935 1,238 30,377 138,035 68,704 31,572 304,713 Doubtful — — — — 178 8,162 3,178 11,518 $ 3,829,674 $ 3,731,808 $ 310,913 $ 1,735,850 $ 178,673 $ 3,208,465 $ 2,290,194 $ 15,285,577 Aging of loans: The following table presents an aging of loans as of December 31, 2017 and 2016 . Amounts include premiums, discounts and deferred fees and costs (in thousands): 2017 2016 Current 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Current 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Non-covered loans: 1-4 single family residential $ 4,145,079 $ 17,224 $ 6,094 $ 5,556 $ 4,173,953 $ 3,457,606 $ 10,355 $ 325 $ 2,063 $ 3,470,349 Home equity loans and lines of credit 1,633 21 — — 1,654 1,120 — — — 1,120 Other consumer loans 19,958 15 — 500 20,473 24,306 — — — 24,306 Multi-family 3,218,953 — — — 3,218,953 3,829,674 — — — 3,829,674 Non-owner occupied commercial real estate 4,464,967 7,549 — 2,285 4,474,801 3,730,470 754 — 584 3,731,808 Construction and land 309,309 — — 1,175 310,484 309,675 — — 1,238 310,913 Owner occupied commercial real estate 2,004,397 1,292 499 6,554 2,012,742 1,726,826 1,557 797 6,670 1,735,850 Commercial and industrial Taxi medallion loans 88,394 6,048 3,333 8,292 106,067 137,856 7,037 4,563 29,217 178,673 Other commercial and industrial 4,025,784 4,291 291 1,394 4,031,760 3,198,008 2,515 954 6,988 3,208,465 Commercial lending subsidiaries 2,561,647 852 — — 2,562,499 2,284,435 12 3,247 2,500 2,290,194 $ 20,840,121 $ 37,292 $ 10,217 $ 25,756 $ 20,913,386 $ 18,699,976 $ 22,230 $ 9,886 $ 49,260 $ 18,781,352 Covered loans: Non-ACI loans: 1-4 single family residential $ 21,076 $ 1,603 $ — $ 1,010 $ 23,689 $ 29,406 $ 481 $ — $ 918 $ 30,805 Home equity loans and lines of credit 30 — — 331 361 43,129 1,255 534 2,077 46,995 $ 21,106 $ 1,603 $ — $ 1,341 $ 24,050 $ 72,535 $ 1,736 $ 534 $ 2,995 $ 77,800 ACI loans: 1-4 single family residential $ 448,125 $ 10,388 $ 2,719 $ 17,836 $ 479,068 $ 500,272 $ 13,524 $ 2,990 $ 15,562 $ 532,348 Home equity loans and lines of credit — — — — — 3,460 148 23 263 3,894 $ 448,125 $ 10,388 $ 2,719 $ 17,836 $ 479,068 $ 503,732 $ 13,672 $ 3,013 $ 15,825 $ 536,242 1-4 single family residential and home equity ACI loans that are contractually delinquent by more than 90 days and accounted for in pools that are on accrual status because discount continues to be accreted totaled $18 million and $16 million at December 31, 2017 and 2016 , respectively. Loan Concentrations: At December 31, 2017 and 2016 , 1-4 single family residential loans outstanding were collateralized by property located in the following states (dollars in thousands): 2017 Percent of Total Non-Covered Loans Covered Loans Total Non-Covered Loans Total Loans California $ 1,094,058 $ 23,780 $ 1,117,838 26.2 % 23.9 % New York 873,360 16,847 890,207 20.9 % 19.0 % Florida 552,556 281,396 833,952 13.2 % 17.8 % Virginia 181,912 22,290 204,202 4.4 % 4.4 % Others 1,472,067 158,444 1,630,511 35.3 % 34.9 % $ 4,173,953 $ 502,757 $ 4,676,710 100.0 % 100.0 % 2016 Percent of Total Non-Covered Loans Covered Loans Total Non-Covered Loans Total Loans California $ 904,107 $ 37,330 $ 941,437 26.1 % 23.3 % Florida 487,294 300,198 787,492 14.0 % 19.5 % New York 763,824 16,403 780,227 22.0 % 19.3 % Virginia 152,113 30,818 182,931 4.4 % 4.5 % Others 1,163,011 178,404 1,341,415 33.5 % 33.4 % $ 3,470,349 $ 563,153 $ 4,033,502 100.0 % 100.0 % No other state represented borrowers with more than 4.0% of 1-4 single family residential loans outstanding at December 31, 2017 or 2016 . At December 31, 2017 , 43.4% and 36.4% of loans in the non-covered commercial portfolio were to borrowers in Florida and the New York tri-state area, respectively. At December 31, 2016 , 43.1% and 39.2% of loans in the non-covered commercial portfolio were to borrowers in Florida and the New York tri-state area, respectively. Foreclosure of residential real estate The carrying amount of foreclosed residential real estate properties included in "Other assets" in the accompanying consolidated balance sheets, all of which were covered, totaled $3 million and $5 million at December 31, 2017 and 2016 , respectively. The recorded investment in residential mortgage loans in the process of foreclosure totaled $11 million and $8 million at December 31, 2017 and 2016 , respectively, substantially all of which were covered loans. Troubled debt restructurings The following tables summarize loans that were modified in TDRs during the years ended December 31, 2017 , 2016 and 2015 , as well as loans modified during the years ended December 31, 2017 , 2016 and 2015 that experienced payment defaults during the periods (dollars in thousands): 2017 Loans Modified in TDRs TDRs Experiencing Payment Number of Recorded Number of Recorded Non-covered loans: 1-4 single family residential 7 $ 676 5 $ 595 Multi-family 2 23,173 — — Owner occupied commercial real estate 3 4,685 — — Commercial and industrial Taxi medallion loans 110 48,526 8 2,725 Other commercial and industrial 2 1,378 — — 124 $ 78,438 13 $ 3,320 2016 Loans Modified in TDRs TDRs Experiencing Payment Number of Recorded Number of Recorded Non-covered loans: 1-4 single family residential 2 $ 326 — $ — Owner occupied commercial real estate 3 5,117 1 491 Commercial and industrial Taxi medallion loans 74 64,854 15 8,657 Other commercial and industrial 8 23,247 2 1,482 Commercial lending subsidiaries 6 6,735 1 2,500 93 $ 100,279 19 $ 13,130 Covered loans: Non-ACI loans: Home equity loans and lines of credit 17 $ 2,016 1 $ 370 ACI loans: Owner occupied commercial real estate 1 $ 825 — $ — 2015 Loans Modified in TDRs TDRs Experiencing Payment Number of Recorded Number of Recorded Non-covered loans: Non-owner occupied commercial real estate 1 $ 548 — $ — Commercial and industrial Taxi medallion loans 2 1,260 1 627 3 $ 1,808 1 $ 627 Covered loans: Non-ACI loans: 1-4 single family residential 2 $ 239 — $ — Home equity loans and lines of credit 28 6,208 7 1,231 30 $ 6,447 7 $ 1,231 ACI loans: Owner occupied commercial real estate 1 $ 500 — $ — Modifications during the years ended December 31, 2017 , 2016 and 2015 included interest rate reductions, restructuring of the amount and timing of required periodic payments, extensions of maturity and covenant waivers. Included in TDRs are residential loans to borrowers who have not reaffirmed their debt discharged in Chapter 7 bankruptcy. The total amount of such loans is not material. Modified ACI loans accounted for in pools are not considered TDRs, are not separated from the pools and are not classified as impaired loans.

FDIC Indemnification Asset

FDIC Indemnification Asset	12 Months Ended
	Dec. 31, 2017
FDIC Indemnification Asset [Abstract]
FDIC Indemnification Asset	FDIC Indemnification Asset When the Company recognizes gains or losses related to covered assets in its consolidated financial statements, changes in the estimated amount recoverable from the FDIC under the Loss Sharing Agreements with respect to those gains or losses are also reflected in the consolidated financial statements. Covered loans may be resolved through prepayment, short sale of the underlying collateral, foreclosure, sale of the loans or charge-off. For loans resolved through prepayment, short sale or foreclosure, the difference between consideration received in satisfaction of the loans and the carrying value of the loans is recognized in the consolidated statement of income line item “ Income from resolution of covered assets, net .” Losses from the resolution of covered loans increase the amount recoverable from the FDIC under the Loss Sharing Agreements. Gains from the resolution of covered loans reduce the amount recoverable from the FDIC under the Loss Sharing Agreements. Similarly, differences in proceeds received on the sale of covered OREO and covered loans and their carrying amounts result in gains or losses and reduce or increase the amount recoverable from the FDIC under the Loss Sharing Agreements. Increases in valuation allowances or impairment charges related to covered assets also increase the amount estimated to be recoverable from the FDIC. These additions to or reductions in amounts recoverable from the FDIC related to transactions in the covered assets are recorded in the consolidated statement of income line item “ Net loss on FDIC indemnification ” and reflected as corresponding increases or decreases in the FDIC indemnification asset. In addition, through June 30, 2017, recoveries of previously indemnified losses on assets that were formerly covered under the Commercial Shared-Loss Agreement resulted in reimbursements due to the FDIC. These transactions are included in the tables below. Amounts payable to the FDIC resulting from these transactions are recognized in other liabilities in the accompanying consolidated balance sheet at December 31, 2016. The following tables summarize the components of the gains and losses associated with covered assets, along with the related additions to or reductions in the amounts recoverable from the FDIC under the Loss Sharing Agreements, as reflected in the consolidated statements of income for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Transaction Net Loss on FDIC Net Impact Provision for losses on covered loans $ (1,358 ) $ 1,039 $ (319 ) Income from resolution of covered assets, net 27,450 (21,912 ) 5,538 Gain on sale of covered loans 17,406 (1,514 ) 15,892 Loss on covered OREO (203 ) 167 (36 ) $ 43,295 $ (22,220 ) $ 21,075 2016 Transaction Net Loss on FDIC Net Impact Recovery of losses on covered loans $ 1,681 $ (1,472 ) $ 209 Income from resolution of covered assets, net 36,155 (28,946 ) 7,209 Loss on sale of covered loans (14,470 ) 11,615 (2,855 ) Loss on covered OREO (1,301 ) 1,044 (257 ) $ 22,065 $ (17,759 ) $ 4,306 2015 Transaction Net Loss on FDIC Net Impact Provision for losses on covered loans $ (2,251 ) $ 1,826 $ (425 ) Income from resolution of covered assets, net 50,658 (40,395 ) 10,263 Gain on sale of covered loans 34,929 (28,051 ) 6,878 Loss on covered OREO (1,014 ) 678 (336 ) $ 82,322 $ (65,942 ) $ 16,380 Changes in the FDIC indemnification asset, and in the liability to the FDIC for recoveries related to assets previously covered under the Commercial Shared-Loss Agreement, for the years ended December 31, 2017 , 2016 and 2015 , were as follows (in thousands): Balance at December 31, 2014 $ 974,335 Amortization (109,411 ) Reduction for claims filed (59,139 ) Net loss on FDIC indemnification (65,942 ) Balance at December 31, 2015 739,843 Amortization (160,091 ) Reduction for claims filed (46,083 ) Net loss on FDIC indemnification (17,759 ) Balance at December 31, 2016 515,910 Amortization (176,466 ) Reduction for claims filed (21,589 ) Net loss on FDIC indemnification (22,220 ) Balance at December 31, 2017 $ 295,635 The balances at December 31, 2017 and 2016 are reflected in the consolidated balance sheets as follows (in thousands): 2017 2016 FDIC indemnification asset $ 295,635 $ 515,933 Other liabilities — (23 ) $ 295,635 $ 515,910

Equipment Under Operating Lease

Equipment Under Operating Lease	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Lessor, Operating Leases [Text Block]	Equipment Under Operating Lease Equipment under operating lease consists primarily of railcars and other transportation equipment. The components of equipment under operating lease as of December 31, 2017 and 2016 are summarized as follows (in thousands): 2017 2016 Equipment under operating lease $ 674,434 $ 589,716 Less: accumulated depreciation (74,932 ) (49,802 ) Equipment under operating lease, net $ 599,502 $ 539,914 The Company recognized impairment of $4.1 million during the year ended December 31, 2016 , related to a group of tank cars impacted by new safety regulations. This impairment charge is included in " Depreciation of equipment under operating lease " in the accompanying consolidated statements of income. No impairment was recognized during the years ended December 31, 2017 and 2015. At December 31, 2017 , scheduled minimum rental payments under operating leases were as follows (in thousands) Years Ending December 31: 2018 $ 50,173 2019 46,547 2020 40,956 2021 31,425 2022 25,185 Thereafter through 2032 58,304 $ 252,590

Premises and Equipment and Leas

Premises and Equipment and Lease Commitments	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment, Type [Abstract]
Property, Plant and Equipment Disclosure [Text Block]	Premises and Equipment and Lease Commitments Premises and equipment are included in other assets in the accompanying consolidated balance sheets and are summarized as follows as of December 31, 2017 and 2016 (in thousands): 2017 2016 Buildings and improvements $ 18,793 $ 22,470 Leasehold improvements 70,298 68,403 Furniture, fixtures and equipment 35,675 36,094 Computer equipment 21,078 18,559 Software and software licensing rights 42,908 38,002 Aircraft and automobiles 11,744 11,857 200,496 195,385 Less: accumulated depreciation (121,477 ) (104,268 ) Premises and equipment, net $ 79,019 $ 91,117 Buildings and improvements includes $11 million related to property under capital lease at both December 31, 2017 and 2016 . Depreciation and amortization expense related to premises and equipment, including amortization of assets recorded under capital leases, was $19.4 million , $21.3 million and $22.9 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company leases branch and office facilities under operating leases, most of which contain renewal options under various terms. Total rent expense under operating leases for the years ended December 31, 2017 , 2016 and 2015 was $27.5 million , $27.6 million , and $27.1 million , respectively. As of December 31, 2017 , future minimum rentals under non-cancelable operating leases with initial or remaining terms in excess of one year were as follows (in thousands): Years ending December 31: 2018 $ 22,340 2019 21,129 2020 17,541 2021 15,770 2022 11,712 Thereafter through 2034 48,183 $ 136,675

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances and Other Borrowings	12 Months Ended
	Dec. 31, 2017
FHLB Advances, Notes and Other Borrowings [Abstract]
Federal Home Loan Bank Advances, Disclosure [Text Block]	Borrowings The following table presents information about outstanding FHLB advances as of December 31, 2017 (dollars in thousands): Range of Interest Rates Amount Minimum Maximum Weighted Average Rate Maturing in: 2018—One month or less $ 2,425,000 1.20 % 1.42 % 1.35 % 2018—Over one month 2,121,000 1.25 % 1.69 % 1.43 % 2019 100,000 1.46 % 1.57 % 1.52 % 2020 125,000 1.67 % 1.78 % 1.73 % Carrying value $ 4,771,000 The table above reflects contractual maturities of outstanding advances and does not incorporate the impact that interest rate swaps designated as cash flow hedges have on the duration of borrowings. The terms of the Company's security agreement with the FHLB require a specific assignment of collateral consisting of qualifying first mortgage loans, commercial real estate loans, home equity lines of credit and mortgage-backed securities with unpaid principal amounts discounted at various stipulated percentages at least equal to 100% of outstanding FHLB advances. As of December 31, 2017 , the Company had pledged investment securities and real estate loans with an aggregate carrying amount of approximately $10.7 billion as collateral for advances from the FHLB. At December 31, 2017 and 2016 outstanding senior notes payable and other borrowings consisted of the following (dollars in thousands): 2017 2016 Principal amount of 4.875% senior notes $ 400,000 $ 400,000 Unamortized discount and debt issuance costs (6,275 ) (6,908 ) 393,725 393,092 Capital lease obligations 9,105 9,717 $ 402,830 $ 402,809 The senior notes mature on November 17, 2025 with interest payable semiannually. The notes have an effective interest rate of 5.12% , after consideration of issuance discount and costs. The notes may be redeemed by the Company, in whole or in part, at any time prior to August 17, 2025 at the greater of a) 100% of the principal balance or b) the sum of the present values of the remaining scheduled payments of principal and interest on the securities discounted to the redemption date at i) the rate on a United States Treasury security with a maturity comparable to the remaining maturity of the senior notes that would be used to price new issues of corporate debt securities with a maturity comparable to the remaining maturity of the senior notes plus ii) 40 basis points. The senior notes may be redeemed at any time after August 17, 2025 at 100% of principal plus accrued and unpaid interest. At December 31, 2017 , BankUnited had available borrowing capacity at the FHLB of approximately $4.1 billion , unused borrowing capacity at the FRB of approximately $770 million and unused Federal funds lines of credit with other financial institutions totaling $70 million .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of the provision (benefit) for income taxes for the years ended December 31, 2017 , 2016 and 2015 were as follows (in thousands): 2017 2016 2015 Current: Federal $ (251,880 ) $ 51,806 $ 18,230 State (15,733 ) 27,708 (2,468 ) (267,613 ) 79,514 15,762 Deferred: Federal 46,377 35,045 20,509 State 11,424 (4,856 ) 8,962 57,801 30,189 29,471 $ (209,812 ) $ 109,703 $ 45,233 A reconciliation of expected income tax expense at the statutory federal income tax rate of 35% to the Company’s effective income tax rate for the years ended December 31, 2017 , 2016 and 2015 follows (dollars in thousands): 2017 2016 2015 Amount Percent Amount Percent Amount Percent Tax expense calculated at the statutory federal income tax rate $ 141,561 35.00 % $ 117,405 35.00 % $ 103,912 35.00 % Increases (decreases) resulting from: Income not subject to tax (29,511 ) (7.30 )% (23,215 ) (6.92 )% (14,279 ) (4.81 )% State income taxes, net of federal tax benefit 19,332 4.78 % 15,894 4.74 % 12,889 4.34 % Uncertain tax positions - lapse of statute of limitations (2,696 ) (0.66 )% — — % (6,166 ) (2.08 )% Discrete income tax benefit (327,945 ) (81.08 )% — — % (49,323 ) (16.61 )% Other, net (10,553 ) (2.61 )% (381 ) (0.12 )% (1,800 ) (0.60 )% $ (209,812 ) (51.87 )% $ 109,703 32.70 % $ 45,233 15.24 % The discrete income tax benefit recognized in the year ended December 31, 2017 related to a matter that arose during an ongoing audit of the Company's 2013 federal income tax return. During that audit, the Company asserted that U.S. federal income taxes paid in respect of certain income previously reported by the Company on its 2012, 2013 and 2014 federal income tax returns related to the basis assigned to certain loans acquired in the FSB Acquisition should be refunded to the Company, in light of guidance issued after the relevant returns had been filed (including Treasury Regulations finalized in October 2017 clarifying and modifying the treatment of such acquired loans). The IRS issued a FAA in the fourth quarter of 2017 agreeing with the Company's position. In light of this communication, the Company concluded that it is more likely than not to realize this income tax benefit and recorded the benefit in the fourth quarter of 2017. Prior to receipt of the FAA, the Company had not taken a position reflecting this benefit on any original or amended income tax returns. The discrete income tax benefit recognized includes expected refunds of federal income tax of $295.0 million , as well as $8.7 million in estimated interest on the federal refund and estimated refunds of $24.2 million from certain state and local taxing jurisdictions. The Company is continuing to evaluate whether it has claims in other state jurisdictions and whether it may have any claims for federal or state income taxes relating to tax years prior to 2012. The Company has not reached any conclusion as to when or to what extent it may have any claims relating to such other state and local taxing jurisdictions or in respect of prior tax years. The discrete income tax benefit recognized in the year ended December 31, 2015 related to additional tax basis recognized with respect to certain assets. The additional tax basis results in increased taxable losses or reduced taxable income upon the final disposition of those assets. The Tax Cuts and Jobs Act of 2017 was signed into law on December 22, 2017, reducing the statutory corporate federal income tax rate from 35 percent to 21 percent, effective January 1, 2018. A tax benefit of $3.7 million , representing the impact of the rate change on deferred tax assets and liabilities existing at the date of enactment, was recognized in earnings during the quarter ended December 31, 2017 and is included in the "Other, net" line item in the reconciliation above. The components of deferred tax assets and liabilities at December 31, 2017 and 2016 were as follows (in thousands): 2017 2016 Deferred tax assets: Excess of tax basis over carrying value of acquired loans $ 66,395 $ 130,004 Allowance for loan and lease losses 33,309 52,670 Net operating loss and tax credit carryforwards 15,892 11,641 Other 31,859 51,911 Gross deferred tax assets 147,455 246,226 Deferred tax liabilities: Net unrealized gains on investment securities available for sale 24,657 30,566 Lease financing, due to differences in depreciation 113,161 145,700 Other 13,468 7,020 Gross deferred tax liabilities 151,286 183,286 Net deferred tax asset (liability) $ (3,831 ) $ 62,940 Based on the evaluation of available evidence, management has concluded that it is more likely than not that the existing deferred tax assets will be realized. The primary factors supporting this conclusion are the amount of taxable income available for carryback and the amount of future taxable income that will result from the scheduled reversal of existing deferred tax liabilities. At December 31, 2017 , remaining carryforwards included federal net operating loss carryforwards in the amount of $10.0 million , expiring from 2029 through 2032, Florida net operating loss carryforwards in the amount of $100.4 million , expiring from 2030 through 2036, and state tax credit carryforwards in the amount of $9.4 million , expiring through 2018. Deferred tax benefits of $2.0 million were recognized for the year ended December 31, 2015 related to enacted changes in state tax laws. The Company has investments in affordable housing limited partnerships which generate federal Low Income Housing Tax Credits and other tax benefits. The balance of these investments, included in other assets in the accompanying consolidated balance sheet, was $64 million and $71 million at December 31, 2017 and 2016 , respectively. Unfunded commitments for affordable housing investments, included in other liabilities in the accompanying consolidated balance sheet, were $26 million and $53 million at December 31, 2017 and 2016 , respectively. The maximum exposure to loss as a result of the Company's involvement with these limited partnerships at December 31, 2017 was approximately $72 million . While the Company believes the likelihood of potential losses from these investments is remote, the maximum exposure was determined by assuming a scenario where the projects completely fail and do not meet certain government compliance requirements resulting in recapture of the related tax credits. These investments did not have a material impact on income tax expense for the years ended December 31, 2017 , 2016 and 2015 . The Company has a liability for unrecognized tax benefits relating to uncertain state tax positions in several jurisdictions. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits for the years ended December 31, 2017 , 2016 and 2015 follows (in thousands): 2017 2016 2015 Balance, beginning of period $ 72,736 $ 43,412 $ 36,622 Additions for tax positions related to the current year 1,882 2,713 2,909 Additions for tax positions related to prior periods 1,661 25,168 11,618 Reductions due to changes in tax positions taken (15,316 ) — — Reductions due to settlements with taxing authorities — (200 ) (246 ) Reductions due to lapse of the statute of limitations (2,229 ) — (5,438 ) 58,734 71,093 45,465 Interest and penalties 486 1,643 (2,053 ) Balance, end of period $ 59,220 $ 72,736 $ 43,412 As of December 31, 2017 , 2016 and 2015 , the Company had $43.6 million , $45.0 million and $27.0 million of unrecognized state tax benefits, net of federal tax benefits, that if recognized would have impacted the effective tax rate. Unrecognized tax benefits related to state income tax contingencies that may decrease during the 12 months subsequent to December 31, 2017 as a result of settlements with taxing authorities range from zero to $41.2 million . Interest and penalties related to unrecognized tax benefits are included in the provision for income taxes in the consolidated statements of income. At December 31, 2017 and 2016 , accrued interest and penalties included in the consolidated balance sheets, net of federal tax benefits, were $3.2 million and $2.5 million , respectively. The total amounts of interest and penalties, net of federal tax benefits, recognized through income tax expense were $0.3 million , $1.1 million and $(1.8) million in 2017 , 2016 and 2015 , respectively. The Company and its subsidiaries file a consolidated federal income tax return as well as combined state income tax returns where combined filings are required. Income tax returns for the tax years ended December 31, 2017 , 2016 , 2015 , 2014 and 2013 remain subject to examination in the U.S. Federal and various state tax jurisdictions. The tax years ended December 31, 2009, 2010, 2011 and 2012 remain subject to examination by certain states.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities The Company uses interest rate swaps to manage interest rate risk related to liabilities that expose the Company to variability in cash flows due to changes in interest rates. The Company enters into LIBOR-based interest rate swaps that are designated as cash flow hedges with the objective of limiting the variability of interest payment cash flows resulting from changes in the benchmark interest rate LIBOR. Changes in the fair value of interest rate swaps designated as cash flow hedging instruments are reported in AOCI and subsequently reclassified into interest expense in the same period in which the related interest on the floating-rate debt obligations affects earnings. The Company also enters into interest rate derivative contracts with certain of its commercial borrowers to enable those borrowers to manage their exposure to interest rate fluctuations. To mitigate interest rate risk associated with these derivative contracts, the Company enters into offsetting derivative contract positions with primary dealers. These interest rate derivative contracts are not designated as hedging instruments; therefore, changes in the fair value of these derivatives are recognized immediately in earnings. The impact on earnings related to changes in fair value of these derivatives for the years ended December 31, 2017 , 2016 and 2015 was not material. The Company may be exposed to credit risk in the event of non-performance by the counterparties to its interest rate derivative agreements. The Company assesses the credit risk of its financial institution counterparties by monitoring publicly available credit rating and financial information. The Company manages dealer credit risk by entering into interest rate derivatives only with primary and highly rated counterparties, the use of ISDA master agreements, central clearing mechanisms and counterparty limits. The agreements contain bilateral collateral arrangements with the amount of collateral to be posted generally governed by the settlement value of outstanding swaps. The Company manages the risk of default by its borrower counterparties through its normal loan underwriting and credit monitoring policies and procedures. The Company does not currently anticipate any losses from failure of interest rate derivative counterparties to honor their obligations. The CME amended its rules effective January 2017 to legally characterize variation margin payments for centrally cleared derivatives as settlements of the derivatives' exposures rather than collateral. As a result, the variation margin payment and the related derivative instruments are considered a single unit of account for accounting and financial reporting purposes. The Company's clearing agent for interest rate derivative contracts centrally cleared through the CME settles the variation margin daily with the CME; therefore, those interest rate derivative contracts the Company clears through the CME are reported at a fair value of approximately zero at December 31, 2017 . The following tables set forth certain information concerning the Company’s interest rate contract derivative financial instruments and related hedged items at December 31, 2017 and 2016 (dollars in thousands): 2017 Weighted Average Pay Rate Weighted Average Receive Rate Weighted Average Remaining Life in Years Notional Amount Balance Sheet Location Fair Value Hedged Item Asset Liability Derivatives designated as cash flow hedges: Pay-fixed interest rate swaps Variability of interest cash flows on variable rate borrowings 1.77% 3-Month Libor 4.3 $ 2,046,000 Other assets / Other liabilities $ 2,350 $ — Derivatives not designated as hedges: Pay-fixed interest rate swaps 3.87% Indexed to 1-month Libor 6.4 1,028,041 Other assets / Other liabilities 10,856 (13,173 ) Pay-variable interest rate swaps Indexed to 1-month Libor 3.87% 6.4 1,028,041 Other assets / Other liabilities 14,410 (12,189 ) Interest rate caps purchased, indexed to 1-month Libor 2.81% 1.3 145,354 Other assets 11 — Interest rate caps sold, indexed to 1-month Libor 2.81% 1.3 145,354 Other liabilities — (11 ) $ 4,392,790 $ 27,627 $ (25,373 ) 2016 Weighted Average Pay Rate Weighted Average Receive Rate Weighted Average Remaining Life in Years Notional Amount Balance Sheet Location Fair Value Hedged Item Asset Liability Derivatives designated as cash flow hedges: Pay-fixed interest rate swaps Variability of interest cash flows on variable rate borrowings 1.58% 3-Month Libor 3.3 $ 1,715,000 Other assets / Other liabilities $ 19,648 $ (3,112 ) Pay-fixed forward-starting interest rate swaps Variability of interest cash flows on variable rate borrowings 3.43% 3-Month Libor 10.5 300,000 Other liabilities — (27,866 ) Derivatives not designated as hedges: Pay-fixed interest rate swaps 3.77% Indexed to 1-month Libor 6.8 912,000 Other assets / Other liabilities 9,949 (20,383 ) Pay-variable interest rate swaps Indexed to 1-month Libor 3.77% 6.8 912,000 Other assets / Other liabilities 20,383 (9,949 ) Interest rate caps purchased, indexed to 1-month Libor 2.96% 2.3 189,057 Other assets 252 — Interest rate caps sold, indexed to 1-month Libor 2.96% 2.3 189,057 Other liabilities — (252 ) $ 4,217,114 $ 50,232 $ (61,562 ) The following table provides information about the amount of loss reclassified from AOCI into interest expense for the years ended December 31, 2017 , 2016 and 2015 (dollars in thousands): Amount of Loss Reclassified from AOCI on Derivatives Location of Loss Reclassified from AOCI into Income 2017 2016 2015 Interest rate contracts $ (9,621 ) $ (16,161 ) $ (21,610 ) Interest expense on borrowings Interest rate contracts — — (4,869 ) Interest expense on deposits $ (9,621 ) $ (16,161 ) $ (26,479 ) During the years ended December 31, 2017 , 2016 and 2015 , no derivative positions designated as cash flow hedges were discontinued and none of the gains and losses reported in AOCI were reclassified into earnings as a result of the discontinuance of cash flow hedges or because of the early extinguishment of debt. As of December 31, 2017 , the amount of net loss expected to be reclassified from AOCI into earnings during the next twelve months was $1.2 million . Some of the Company’s ISDA master agreements with financial institution counterparties contain provisions that permit either counterparty to terminate the agreements and require settlement in the event that regulatory capital ratios fall below certain designated thresholds, upon the initiation of other defined regulatory actions or upon suspension or withdrawal of the Bank’s credit rating. Currently, there are no circumstances that would trigger these provisions of the agreements. The Company does not offset assets and liabilities under master netting agreements for financial reporting purposes. Information on interest rate swaps subject to these agreements is as follows at December 31, 2017 and 2016 (in thousands): 2017 Gross Amounts Offset in Balance Net Amounts Presented in Gross Amounts Not Offset in Balance Sheet Gross Amounts Recognized Derivative Instruments Collateral Pledged Net Amount Derivative assets $ 13,217 $ — $ 13,217 $ (7,996 ) $ (5,221 ) $ — Derivative liabilities (13,173 ) — (13,173 ) 7,996 4,962 (215 ) $ 44 $ — $ 44 $ — $ (259 ) $ (215 ) 2016 Gross Amounts Offset in Balance Net Amounts Presented in Gross Amounts Not Offset in Balance Sheet Gross Amounts Recognized Derivative Instruments Collateral Pledged Net Amount Derivative assets $ 29,849 $ — $ 29,849 $ (27,485 ) $ — $ 2,364 Derivative liabilities (51,362 ) — (51,362 ) 27,485 23,796 (81 ) $ (21,513 ) $ — $ (21,513 ) $ — $ 23,796 $ 2,283 The difference between the amounts reported for interest rate swaps subject to master netting agreements and the total fair value of interest rate contract derivative financial instruments reported in the consolidated balance sheets is related to interest rate contracts entered into with borrowers not subject to master netting agreements. At December 31, 2017 , the Company had pledged investment securities available for sale with a carrying amount of $31 million as collateral for interest rate swaps in a liability position. Financial collateral of $7.0 million was pledged by counterparties to the Company for interest rate swaps in an asset position. The amount of collateral required to be posted varies based on the settlement value of outstanding swaps and in some cases may include initial margin requirements.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Accumulated Other Comprehensive Income Changes in AOCI are summarized as follows for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Before Tax Tax Effect Net of Tax Unrealized gains on investment securities available for sale: Net unrealized holding gain arising during the period $ 49,131 $ (19,407 ) $ 29,724 Amounts reclassified to gain on investment securities available for sale, net (33,466 ) 13,219 (20,247 ) Net change in unrealized gains on investment securities available for sale 15,665 (6,188 ) 9,477 Unrealized losses on derivative instruments: Net unrealized holding loss arising during the period (2,577 ) 1,018 (1,559 ) Amounts reclassified to interest expense on borrowings 9,621 (3,800 ) 5,821 Net change in unrealized losses on derivative instruments 7,044 (2,782 ) 4,262 Other comprehensive income $ 22,709 $ (8,970 ) $ 13,739 2016 Before Tax Tax Effect Net of Tax Unrealized gains on investment securities available for sale: Net unrealized holding gain arising during the period $ 23,588 $ (9,317 ) $ 14,271 Amounts reclassified to gain on investment securities available for sale, net (14,461 ) 5,712 (8,749 ) Net change in unrealized gains on investment securities available for sale 9,127 (3,605 ) 5,522 Unrealized losses on derivative instruments: Net unrealized holding gain arising during the period 6,225 (2,459 ) 3,766 Amounts reclassified to interest expense on borrowings 16,161 (6,384 ) 9,777 Net change in unrealized losses on derivative instruments 22,386 (8,843 ) 13,543 Other comprehensive income $ 31,513 $ (12,448 ) $ 19,065 2015 Before Tax Tax Effect Net of Tax Unrealized gains on investment securities available for sale: Net unrealized holding loss arising during the period $ (34,470 ) $ 12,813 $ (21,657 ) Amounts reclassified to gain on investment securities available for sale, net (8,480 ) 3,350 (5,130 ) Net change in unrealized gains on investment securities available for sale (42,950 ) 16,163 (26,787 ) Unrealized losses on derivative instruments: Net unrealized holding loss arising during the period (22,635 ) 9,232 (13,403 ) Amounts reclassified to interest expense on deposits 4,869 (1,923 ) 2,946 Amounts reclassified to interest expense on borrowings 21,610 (8,536 ) 13,074 Net change in unrealized losses on derivative instruments 3,844 (1,227 ) 2,617 Other comprehensive loss $ (39,106 ) $ 14,936 $ (24,170 ) The categories of AOCI and changes therein are presented below for the years ended December 31, 2017 , 2016 and 2015 (in thousands): Unrealized Gains on Investment Securities Available for Sale Unrealized Losses on Derivative Instruments Total Balance at December 31, 2014 $ 68,322 $ (21,970 ) $ 46,352 Other comprehensive loss (26,787 ) 2,617 (24,170 ) Balance at December 31, 2015 $ 41,535 $ (19,353 ) $ 22,182 Other comprehensive income 5,522 13,543 19,065 Balance at December 31, 2016 $ 47,057 $ (5,810 ) $ 41,247 Other comprehensive income 9,477 4,262 13,739 Balance at December 31, 2017 $ 56,534 $ (1,548 ) $ 54,986 Other In conjunction with a previous acquisition, the Company issued 1,834,160 warrants to purchase its common stock. The warrants expire in November 2018 and are exercisable at an exercise price of $9.47 , in exchange for which the holder is entitled to receive 0.0827 shares of BKU common stock and cash of $1.73 . In January 2018, our Board of Directors authorized a share repurchase program under which the Company may repurchase up to $150 million of its outstanding common stock. Any repurchases will be made in accordance with applicable securities laws from time to time in open market or private transactions. The authorization does not require the Company to acquire any specified number of common shares and may be commenced, suspended or discontinued without prior notice.

Equity Based Compensation

Equity Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Based Compensation	Equity Based and Other Compensation Plans Description of Equity Based Compensation Plans In connection with the IPO of the Company's common stock in 2011, the Company adopted the 2010 Plan. In 2014, the Board of Directors and the Company's stockholders approved the 2014 Plan. The 2010 Plan and 2014 Plans are administered by the Board of Directors or a committee thereof and provide for the grant of non-qualified stock options, SARs, restricted shares, deferred shares, performance shares, unrestricted shares and other share-based awards to selected employees, directors or independent contractors of the Company and its affiliates. The number of shares of common stock authorized for award under the 2010 Plan is 7,500,000 , of which 246,151 shares remain available for issuance as of December 31, 2017 . The number of shares of common stock available for issuance under the 2014 Plan is 4,000,000 , of which 2,892,439 shares remain available for issuance as of December 31, 2017 . Shares of common stock delivered under the plans may consist of authorized but unissued shares or previously issued shares reacquired by the Company. The term of a share option or SAR issued under the plans may not exceed ten years from the date of grant and the exercise price may not be less than the fair market value of the Company's common stock at the date of grant. Unvested awards generally become fully vested in the event of a change in control, as defined. Compensation Expense Related to Equity Based Awards The following table summarizes compensation cost related to equity based awards for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 2016 2015 Compensation cost of equity based awards: Unvested and restricted share awards $ 18,087 $ 16,885 $ 15,573 Executive share-based awards 3,416 1,482 294 Incentive awards 1,289 — — Total compensation cost of equity based awards 22,792 18,367 15,867 Related tax benefits (8,576 ) (6,899 ) (5,965 ) Compensation cost of equity based awards, net of tax $ 14,216 $ 11,468 $ 9,902 Share Awards Unvested share awards A summary of activity related to unvested share awards for the years ended December 31, 2017 , 2016 and 2015 follows: Number of Share Awards Weighted Average Grant Date Fair Value Unvested share awards outstanding, December 31, 2014 829,225 $ 30.06 Granted 664,928 32.06 Vested (394,498 ) 28.72 Canceled or forfeited (59,270 ) 29.82 Unvested share awards outstanding, December 31, 2015 1,040,385 31.86 Granted 651,760 31.00 Vested (428,167 ) 31.79 Canceled or forfeited (143,278 ) 31.31 Unvested share awards outstanding, December 31, 2016 1,120,700 31.46 Granted 621,806 40.24 Vested (553,007 ) 31.67 Canceled or forfeited (81,022 ) 34.51 Unvested share awards outstanding, December 31, 2017 1,108,477 $ 36.06 Unvested share awards are generally valued at the closing price of the Company's common stock on the date of grant. The following table summarizes the closing price of the Company's stock on the date of grant for shares granted and the aggregate grant date fair value of shares vesting during the years ended December 31, 2017 , 2016 , and 2015 (in thousands, except per share data): 2017 2016 2015 Range of the closing price on date of grant $33.21 - $40.84 $29.78 - $33.76 $31.35 - $38.63 Aggregate grant date fair value of shares vesting $ 17,514 $ 13,613 $ 11,330 Substantially all of the shares vest in equal annual installments over a period of three years from the date of grant. Unvested shares participate in dividends declared on the Company's common stock on a one-for-one basis. Unrecognized compensation cost for unvested share awards outstanding at December 31, 2017 totaled $22.7 million , which will be recognized over a weighted average remaining period of 1.84 years . Executive share-based awards Certain of the Company's executives are eligible to receive annual awards of RSUs and PSUs (collectively, the "share units"). Annual awards of RSUs represent a fixed number of shares and vest in equal tranches over three years . PSUs are initially granted based on a target value. The numb er of PSUs that ultimately vest at the end of a three-year performance measurement period will be based on the achievement of performance criteria pre-established by the Compensation Committee of the Board of Directors. The performance criteria established for the PSUs granted in 2017 and 2016 include both performance and market conditions. Upon vesting, the share units will be converted to common stock on a one-for-one basis, or may be settled in cash at the Company's option. The share units will accumulate dividends declared on the Company's common stock from the date of grant to be paid subsequent to vesting. A summary of activity related to executive share-based awards for the years ended December 31, 2017 and 2016 follows: RSU PSU Unvested executive share-based awards outstanding, December 31, 2015 — — Granted 97,852 57,873 Vested (19,291 ) — Unvested executive share-based awards outstanding, December 31, 2016 78,561 57,873 Granted 47,848 47,848 Vested (35,241 ) — Unvested executive share-based awards outstanding, December 31, 2017 91,168 105,721 RSUs granted during the year ended December 31, 2016 included a grant of 39,979 RSUs that vest five years from the date of grant. The first tranche of RSUs granted vested on December 31, 2016. The Company cash settled these share units in the amount of $0.8 million during the first quarter of 2017. As a result of this cash settlement, all RSUs and PSUs have been determined to be liability instruments and will be remeasured at fair value each reporting period until the awards are settled. The RSUs vested on December 31, 2017 will be settled during the first quarter of 2018. The RSUs are valued based on the closing price of the Company's common stock at the reporting date. The PSUs are valued based on the closing price of the Company's common stock at the reporting date net of a discount related to any applicable market conditions, considering the probability of meeting the defined performance conditions. Compensation cost related to PSUs is recognized during the performance period based on the probable outcome of the respective performance conditions. The total liability for these executive share-based awards was $3.9 million at December 31, 2017 . The total unrecognized compensation cost of $5.3 million for unvested executive share-based awards at December 31, 2017 will be recognized over a weighted average remaining period of 2.07 years . Based on the closing price of the Company's common stock on the date of grant, 25,321 and 41,645 unvested share awards were granted to certain of the Company's executives in 2017 and 2015, respectively, based on the achievement of performance criteria pre-established by the Compensation Committee . These shares are included in the summary of activity related to unvested share awards above. Incentive awards Beginning in 2017, the Company's annual incentive compensation arrangements provide for settlement through a combination of cash payments and unvested share awards following the end of the annual performance period. The dollar value of share awards to be granted is based on the achievement of performance criteria established in the incentive arrangements. The number of shares of common stock to be awarded is variable based on the closing price of the Company's stock on the date of grant; therefore, these awards are initially classified as liability instruments, with compensation cost recognized from the beginning of the performance period. The awards vest in equal installments over a period of three years from the date of grant. The total liability for the incentive share awards was $1.3 million at December 31, 2017 . The total unrecognized compensation cost of $3.9 million for these share awards at December 31, 2017 will be recognized over a weighted average remaining period of 3.00 years . Option Awards A summary of activity related to stock option awards for the years ended December 31, 2017 , 2016 and 2015 follows: Number of Option Awards Weighted Average Exercise Price Option awards outstanding, December 31, 2014 5,015,047 $ 26.49 Exercised (1,363,895 ) 26.14 Option awards outstanding, December 31, 2015 3,651,152 26.62 Exercised (47,979 ) 16.50 Canceled or forfeited (1,097 ) 63.74 Option awards outstanding, December 31, 2016 3,602,076 26.74 Exercised (2,331,388 ) 26.63 Option awards outstanding and exercisable, December 31, 2017 1,270,688 $ 26.93 The intrinsic value of options exercised during the years ended December 31, 2017 , 2016 and 2015 was $25.8 million , $0.9 million and $8.7 million , respectively. There were no option awards granted during the years ended December 31, 2017 , 2016 and 2015 . Additional information about options outstanding and exercisable at December 31, 2017 is presented in the following table: Outstanding and Exercisable Options Range of Exercise Prices Number of Options Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) $11.14 13,160 1.73 $ 389 $15.94 - $19.97 29,145 2.59 672 $22.18 - $22.31 41,417 3.47 764 $27 1,170,847 3.08 16,064 $63.74 16,119 0.93 — 1,270,688 3.04 $ 17,889 Deferred Compensation Plan The Company has a non-qualified deferred compensation plan for a select group of key management or highly compensated employees whereby a participant, upon election, may defer a portion of eligible compensation. The deferred compensation plan provides for discretionary Company contributions. Generally, the Company has elected not to make contributions. The Company credits each participant's account with income based on either an annual interest rate determined by the Company's Compensation Committee or returns of selected investment portfolios, as elected by the participant. A participant's elective deferrals and interest thereon are at all times 100% vested. Company contributions and interest thereon will become 100% vested upon the earlier of a change in control, as defined, or the participant's death, disability, attainment of normal retirement age or the completion of two years of service. Participant deferrals and any associated earnings will be paid upon separation from service or based on a specified distribution schedule, as elected by the participant. Deferred compensation expense was $1.5 million , $1.5 million and $0.8 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. Deferred compensation liabilities of $21 million and $20 million were included in other liabilities in the accompanying consolidated balance sheets at December 31, 2017 and 2016 , respectively. BankUnited 401(k) Plan Under the terms of the 401(k) Plan sponsored by the Company, eligible employees may contribute a portion of compensation not exceeding the limits set by law. Employees are eligible to participate in the plan after one month of service. The 401(k) Plan allows a matching employer contribution equal to 100% of elective deferrals that do not exceed 1% of compensation, plus 70% of elective deferrals that exceed 1% but are less than 6% of compensation. Matching contributions are fully vested after two years of service. For the years ended December 31, 2017 , 2016 and 2015 , BankUnited made matching contributions to the 401(k) Plan of approximately $5.5 million , $5.2 million and $4.9 million , respectively.

Regulatory Requirements and Res

Regulatory Requirements and Restrictions	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital Requirements under Banking Regulations [Text Block]	Note 15 Regulatory Requirements and Restrictions The Company and the Bank are subject to various regulatory capital requirements administered by Federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory—and possibly additional discretionary—actions by regulators that, if undertaken, could have a direct material effect on the Company's financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of assets, liabilities and certain off-balance-sheet items calculated pursuant to regulation. The capital amounts and classification also are subject to qualitative judgments by the regulators about components, risk weightings and other factors. Banking regulations identify five capital categories for insured depository institutions: well-capitalized, adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized. As of December 31, 2017 and 2016 , all capital ratios of the Company and the Bank exceeded the "well capitalized" levels under the regulatory framework for prompt corrective action. Quantitative measures established by regulation to ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios of total, common equity tier 1 and tier 1 capital (as defined in the regulations) to risk-weighted assets (as defined), and of tier 1 capital to average tangible assets (leverage ratio). The following tables provide information regarding regulatory capital for the Company and the Bank as of December 31, 2017 and 2016 (dollars in thousands): 2017 Actual Required to be Considered Well Capitalized Required to be Considered Adequately Capitalized Amount Ratio Amount Ratio Amount Ratio BankUnited, Inc.: Tier 1 leverage $ 2,892,069 9.72 % N/A (1) N/A (1) $ 1,189,944 4.00 % CET1 risk-based capital $ 2,892,069 13.11 % $ 1,434,193 6.50 % $ 992,903 4.50 % Tier 1 risk-based capital $ 2,892,069 13.11 % $ 1,765,161 8.00 % $ 1,323,871 6.00 % Total risk based capital $ 3,041,004 13.78 % $ 2,206,451 10.00 % $ 1,765,161 8.00 % BankUnited: Tier 1 leverage $ 3,107,920 10.47 % $ 1,483,796 5.00 % $ 1,187,037 4.00 % CET1 risk-based capital $ 3,107,920 14.13 % $ 1,429,999 6.50 % $ 989,999 4.50 % Tier 1 risk-based capital $ 3,107,920 14.13 % $ 1,759,999 8.00 % $ 1,319,999 6.00 % Total risk based capital $ 3,255,221 14.80 % $ 2,199,999 10.00 % $ 1,759,999 8.00 % 2016 Actual Required to be Considered Well Capitalized Required to be Considered Adequately Capitalized Amount Ratio Amount Ratio Amount Ratio BankUnited, Inc.: Tier 1 leverage $ 2,298,450 8.41 % N/A (1) N/A (1) $ 1,092,921 4.00 % CET1 risk-based capital $ 2,298,450 11.63 % $ 1,284,498 6.50 % $ 889,268 4.50 % Tier 1 risk-based capital $ 2,298,450 11.63 % $ 1,580,921 8.00 % $ 1,185,691 6.00 % Total risk based capital $ 2,459,470 12.45 % $ 1,976,151 10.00 % $ 1,580,921 8.00 % BankUnited: Tier 1 leverage $ 2,534,402 9.30 % $ 1,361,959 5.00 % $ 1,089,567 4.00 % CET1 risk-based capital $ 2,534,402 12.89 % $ 1,278,277 6.50 % $ 884,961 4.50 % Tier 1 risk-based capital $ 2,534,402 12.89 % $ 1,573,265 8.00 % $ 1,179,948 6.00 % Total risk based capital $ 2,694,048 13.70 % $ 1,966,581 10.00 % $ 1,573,265 8.00 % (1) There is no Tier 1 leverage ratio component in the definition of a well-capitalized bank holding company. For purposes of risk based capital computations, the FDIC Indemnification asset and the covered assets are risk-weighted at 20% due to the conditional guarantee represented by the Loss Sharing Agreements. BankUnited is subject to various regulatory restrictions relating to the payment of dividends, including requirements to maintain capital at or above certain minimums, and to remain "well-capitalized" under the prompt corrective action regulations. The Company does not expect that any of these laws, regulations or policies will materially affect the ability of BankUnited to pay dividends in the future. Levels of capital required to be well capitalized or adequately capitalized as reflected above do not include a capital conservation buffer that is being phased in between 2016 and 2019. When fully phased in on January 1, 2019, the Bank and the Company will have to maintain this capital conservation buffer composed of CET1 capital equal to 2.50% of risk-weighted assets above the amounts required to be adequately capitalized, as reflected above, in order to avoid limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers. Capital ratios required to be considered well-capitalized exceed the ratios required under the capital conservation buffer requirement at December 31, 2017 . BankUnited is required by the Board of Governors of the Federal Reserve System to maintain reserve balances in the form of vault cash or deposits with the FRB. At December 31, 2017 , the reserve requirement for BankUnited was $91 million .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Assets and liabilities measured at fair value on a recurring basis Following is a description of the methodologies used to estimate the fair values of assets and liabilities measured at fair value on a recurring basis and the level within the fair value hierarchy in which those measurements are typically classified. Investment securities available for sale —Fair value measurements are based on quoted prices in active markets when available; these measurements are classified within level 1 of the fair value hierarchy. These securities typically include U.S. Treasury securities and certain preferred stocks. If quoted prices in active markets are not available, fair values are estimated using quoted prices of securities with similar characteristics, quoted prices of identical securities in less active markets, discounted cash flow techniques, or matrix pricing models. These securities are generally classified within level 2 of the fair value hierarchy and include U.S. Government agency securities, U.S. Government agency and sponsored enterprise MBS, preferred stock investments for which level 1 valuations are not available, corporate debt securities, non-mortgage asset-backed securities, single family rental real estate-backed securities, certain private label residential MBS and CMOs, private label commercial MBS, collateralized loan obligations and state and municipal obligations. Pricing of these securities is generally primarily spread driven. Observable inputs that may impact the valuation of these securities include benchmark yield curves, credit spreads, reported trades, dealer quotes, bids, issuer spreads, current rating, historical constant prepayment rates, historical voluntary prepayment rates, structural and waterfall features of individual securities, published collateral data, and for certain securities, historical constant default rates and default severities. Investment securities available for sale generally classified within level 3 of the fair value hierarchy include certain private label MBS and trust preferred securities. The Company typically values these securities using third-party proprietary pricing models, primarily discounted cash flow valuation techniques, which incorporate both observable and unobservable inputs. Unobservable inputs that may impact the valuation of these securities include risk adjusted discount rates, projected prepayment rates, projected default rates and projected loss severity. The Company uses third-party pricing services in determining fair value measurements for investment securities. To obtain an understanding of the methodologies and assumptions used, management reviews written documentation provided by the pricing services, conducts interviews with valuation desk personnel and reviews model results and detailed assumptions used to value selected securities as considered necessary. Management has established a robust price challenge process that includes a review by the treasury front office of all prices provided on a monthly basis. Any price evidencing unexpected month over month fluctuations or deviations from expectations is challenged. If considered necessary to resolve any discrepancies, a price will be obtained from an additional independent valuation source. The Company does not typically adjust the prices provided, other than through this established challenge process. The results of price challenges are subject to review by executive management. The Company has also established a quarterly process whereby prices provided by its primary pricing service for a sample of securities are validated. Any price discrepancies are resolved based on careful consideration of the assumptions and inputs employed by each of the pricing sources. Servicing rights —Commercial servicing rights are valued using a discounted cash flow methodology incorporating contractually specified servicing fees and market based assumptions about prepayments, discount rates, default rates and costs of servicing. Prepayment and default assumptions are based on historical industry data for loans with similar characteristics. Assumptions about costs of servicing are based on market convention. Discount rates are based on rates of return implied by observed trades of underlying loans in the secondary market. Fair value of residential MSRs is estimated using a discounted cash flow technique that incorporates market‑based assumptions including estimated prepayment speeds, contractual servicing fees, cost to service, discount rates, escrow account earnings, ancillary income, and estimated defaults. Due to the nature of the valuation inputs and the limited availability of market pricing, servicing rights are classified as level 3. Derivative financial instruments —Fair values of interest rate swaps are determined using widely accepted discounted cash flow modeling techniques. These discounted cash flow models use projections of future cash payments and receipts that are discounted at mid-market rates. Observable inputs that may impact the valuation of these instruments include LIBOR swap rates and LIBOR forward yield curves. These fair value measurements are generally classified within level 2 of the fair value hierarchy. The following tables present assets and liabilities measured at fair value on a recurring basis at December 31, 2017 and 2016 (in thousands): 2017 Level 1 Level 2 Level 3 Total Investment securities available for sale: U.S. Treasury securities $ 24,953 $ — $ — $ 24,953 U.S. Government agency and sponsored enterprise residential MBS — 2,058,027 — 2,058,027 U.S. Government agency and sponsored enterprise commercial MBS — 234,508 — 234,508 Private label residential MBS and CMOs — 576,033 52,214 628,247 Private label commercial MBS — 1,046,415 — 1,046,415 Single family rental real estate-backed securities — 562,706 — 562,706 Collateralized loan obligations — 723,681 — 723,681 Non-mortgage asset-backed securities — 121,747 — 121,747 Preferred stocks 63,543 — — 63,543 State and municipal obligations — 657,203 — 657,203 SBA securities — 550,682 — 550,682 Other debt securities — 3,791 5,329 9,120 Servicing rights — — 30,737 30,737 Derivative assets — 27,627 — 27,627 Total assets at fair value $ 88,496 $ 6,562,420 $ 88,280 $ 6,739,196 Derivative liabilities $ — $ 25,373 $ — $ 25,373 Total liabilities at fair value $ — $ 25,373 $ — $ 25,373 2016 Level 1 Level 2 Level 3 Total Investment securities available for sale: U.S. Treasury securities $ 5,005 $ — $ — $ 5,005 U.S. Government agency and sponsored enterprise residential MBS — 1,527,242 — 1,527,242 U.S. Government agency and sponsored enterprise commercial MBS — 124,586 — 124,586 Private label residential MBS and CMOs — 254,488 120,610 375,098 Private label commercial MBS — 1,187,624 — 1,187,624 Single family rental real estate-backed securities — 861,251 — 861,251 Collateralized loan obligations — 487,296 — 487,296 Non-mortgage asset-backed securities — 186,736 — 186,736 Preferred stocks 86,890 1,313 — 88,203 State and municipal obligations — 698,546 — 698,546 SBA securities — 523,906 — 523,906 Other debt securities — 3,519 4,572 8,091 Servicing rights — — 27,159 27,159 Derivative assets — 50,232 — 50,232 Total assets at fair value $ 91,895 $ 5,906,739 $ 152,341 $ 6,150,975 Derivative liabilities $ — $ 61,562 $ — $ 61,562 Total liabilities at fair value $ — $ 61,562 $ — $ 61,562 There were no transfers of financial assets between levels of the fair value hierarchy during the years ended December 31, 2017 and 2016 . The following tables reconcile changes in the fair value of assets and liabilities measured at fair value on a recurring basis and classified in level 3 of the fair value hierarchy during the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 120,610 $ 4,572 $ 27,159 Gains (losses) for the period included in: Net income 25,547 — (5,821 ) Other comprehensive income (27,569 ) 766 — Discount accretion 6,181 280 — Purchases or additions — — 9,399 Sales (45,524 ) — — Settlements (27,031 ) (289 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 52,214 $ 5,329 $ 30,737 2016 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 140,883 $ 4,532 $ 20,017 Gains (losses) for the period included in: Net income — — (6,023 ) Other comprehensive income (2,229 ) (9 ) — Discount accretion 5,947 116 — Purchases or additions — — 13,165 Settlements (23,991 ) (67 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 120,610 $ 4,572 $ 27,159 2015 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 168,077 $ 4,918 $ — Gains (losses) for the period included in: Net income — — (2,062 ) Other comprehensive income (7,469 ) (434 ) — Discount accretion 6,524 148 — Purchases or additions — — 13,610 Settlements (26,249 ) (100 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 140,883 $ 4,532 $ 11,548 The balance of servicing rights at the beginning of 2016 includes $8.5 million of residential MSRs, which the Company elected to measure at fair value effective January 1, 2016. Gains on private label residential MBS recognized in net income during the year ended December 31, 2017 are included in the consolidated statement of income line item " Gain on investment securities available for sale, net ." Changes in the fair value of servicing rights are included in the consolidated statement of income line item “ Other non-interest income .” Changes in fair value include changes due to valuation assumptions, primarily discount rates and prepayment speeds, as well as other changes such as runoff and the passage of time. The amount of net unrealized losses included in earnings for the years ended December 31, 2017 and 2016 that were related to servicing rights held at December 31, 2017 and 2016 totaled approximately $1.0 million and $1.8 million , respectively, and were primarily due to changes in discount rates and prepayment speeds. Securities for which fair value measurements are categorized in level 3 of the fair value hierarchy at December 31, 2017 consisted of pooled trust preferred securities with a fair value of $5 million and private label residential MBS and CMOs with a fair value of $52 million . The trust preferred securities are not material to the Company’s financial statements. Private label residential MBS consisted of senior and mezzanine tranches collateralized by prime fixed rate and hybrid 1-4 single family residential mortgages originated before 2005, some of which contain option-arm features. Substantially all of these securities have variable rate coupons. Weighted average subordination levels at December 31, 2017 were 17.3% and 9.7% for investment grade and non-investment grade securities, respectively. The following table provides information about the valuation techniques and unobservable inputs used in the valuation of private label residential MBS and CMOs falling within level 3 of the fair value hierarchy as of December 31, 2017 (dollars in thousands): Fair Value at Valuation Technique Unobservable Input Range (Weighted Average) December 31, 2017 Investment grade $ 32,997 Discounted cash flow Voluntary prepayment rate 9.00% - 27.80% (16.94%) Probability of default 0.00% - 4.10% (1.18%) Loss severity 15.00% - 86.00% (30.56%) Discount rate 1.68% - 8.11% (3.64%) Non-investment grade $ 19,217 Discounted cash flow Voluntary prepayment rate 0.70% - 27.80% (15.37%) Probability of default 0.00% - 7.00% (2.00%) Loss severity 15.00% - 83.00% (31.04%) Discount rate 2.31% - 9.13% (6.03%) The significant unobservable inputs impacting the fair value measurement of private label residential MBS and CMOs include voluntary prepayment rates, probability of default, loss severity given default and discount rates. Generally, increases in probability of default, loss severity or discount rates would result in a lower fair value measurement. Alternatively, decreases in probability of default, loss severity or discount rates would result in a higher fair value measurement. For securities with less favorable credit characteristics, decreases in voluntary prepayment speeds may be interpreted as a deterioration in the overall credit quality of the underlying collateral and as such, lead to lower fair value measurements. The fair value measurements of those securities with higher levels of subordination will be less sensitive to changes in these unobservable inputs other than discount rates, while securities with lower levels of subordination will show a higher degree of sensitivity to changes in these unobservable inputs other than discount rates. Generally, a change in the assumption used for probability of default is accompanied by a directionally similar change in the assumption used for loss severity given default and a directionally opposite change in the assumption used for voluntary prepayment rate. The following table provides information about the valuation techniques and significant unobservable inputs used in the valuation of servicing rights as of December 31, 2017 (dollars in thousands): Fair Value at Valuation Technique Unobservable Input Range (Weighted Average) December 31, 2017 Residential MSRs $ 19,622 Discounted cash flow Prepayment rate 7.31% - 26.98% (12.12%) Discount rate 9.50% - 9.58% (9.51%) Commercial servicing rights $ 11,115 Discounted cash flow Prepayment rate 0.66% - 10.99% (8.79%) Discount rate 8.41% - 15.26% (12.69%) Increases in prepayment rates or discount rates would result in lower fair value measurements and decreases in prepayment rates or discount rates would result in higher fair value measurements. Although the prepayment rate and the discount rate are not directly interrelated, they generally move in opposite directions. Assets and liabilities measured at fair value on a non-recurring basis Following is a description of the methodologies used to estimate the fair values of assets and liabilities that may be measured at fair value on a non-recurring basis, and the level within the fair value hierarchy in which those measurements are typically classified. Impaired loans, OREO and other repossessed assets —The carrying amount of collateral dependent impaired loans is typically based on the fair value of the underlying collateral, which may be real estate, taxi medallions, or other business assets, less estimated costs to sell. The carrying value of OREO is initially measured based on the fair value of the real estate acquired in foreclosure and subsequently adjusted to the lower of cost or estimated fair value, less estimated cost to sell. Fair values of real estate collateral and OREO are typically based on third-party real estate appraisals which utilize market and income approaches to valuation incorporating both observable and unobservable inputs. When current appraisals are not available, the Company may use brokers’ price opinions, home price indices or other available information about changes in real estate market conditions to adjust the latest appraised value available. These adjustments to appraised values may be subjective and involve significant management judgment. The fair value of repossessed assets, other than taxi medallions, or collateral consisting of other business assets may be based on third-party appraisals or internal analyses that use market approaches to valuation incorporating primarily unobservable inputs. The fair value of New York City taxi medallions is based primarily on an internal analysis that utilizes an income approach to valuation. This analysis utilizes data obtained from the NYTLC about the fleet in general and in some cases, our portfolio specifically, and management's assumptions, based on external data when available, about revenues, costs and expenses, to estimate the value that can reasonably be supported by the cash flow generating capacity of a medallion. We further discount the results of this analysis in recognition of estimated selling costs and declining trends in medallion values. We also consider prices of recent medallion transfers as published by the NYTLC; however, the market for taxi medallions is illiquid and information about the circumstances underlying observed transfers is unavailable, therefore, information about recent transfers is not considered sufficient to establish a reliable estimate of value. Taxi medallions in municipalities other than New York City are generally valued based on published information about recent transfer prices; the valuation of these assets did not have a material impact on the Company's consolidated financial statements for any period presented as the taxi medallion portfolio is heavily concentrated in New York City. Fair value measurements related to collateral dependent impaired loans, OREO and other repossessed assets are classified within level 3 of the fair value hierarchy. Equipment under operating lease —Fair values of equipment under operating lease are typically based upon discounted cash flow analysis, considering expected lease rates and estimated end of life residual values. These fair value measurements are classified within level 3 of the fair value hierarchy. The following tables present the carrying value of assets for which non-recurring changes in fair value have been recorded for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Losses from Fair Value Changes Level 1 Level 2 Level 3 Total Years Ended OREO and repossessed assets $ — $ — $ 5,790 $ 5,790 $ (2,078 ) Impaired loans $ — $ — $ 93,051 $ 93,051 $ (65,716 ) 2016 Losses from Fair Value Changes Level 1 Level 2 Level 3 Total Years Ended OREO and repossessed assets $ — $ — $ 12,466 $ 12,466 $ (1,156 ) Impaired loans $ — $ — $ 78,121 $ 78,121 $ (25,573 ) Equipment under operating lease $ — — $ — $ 8,173 $ 8,173 $ (4,100 ) 2015 Losses from Fair Value Changes Level 1 Level 2 Level 3 Total Years Ended OREO and repossessed assets $ — $ — $ 7,389 $ 7,389 $ (1,206 ) Impaired loans $ — $ — $ 30,812 $ 30,812 $ (9,865 ) Residential MSRs $ — $ — $ 8,469 $ 8,469 $ (15 ) Included in the tables above are impaired taxi medallion loans with carrying values of $86.0 million and $50.7 million at December 31, 2017 and 2016 , respectively, the majority of which were in New York City. Losses of $62.4 million and $12.7 million were recognized on impaired taxi medallion loans during the years ended December 31, 2017 and 2016 , respectively. There were no impaired taxi medallion loans at December 31, 2015. In addition, OREO and repossessed assets reported above included repossessed taxi medallions with carrying values of $ 2.1 million and $2.5 million at December 31, 2017 and 2016 , respectively. Losses of $1.3 million and $0.2 million were recognized on repossessed taxi medallions during the years ended December 31, 2017 and 2016 , respectively. Decreases in the value of medallions are largely driven by decreases in revenues generated from the medallions. Inputs that had the most significant impact on the valuation of New York City taxi medallions at December 31, 2017 are presented below: Average Amount Average fare per trip $16.04 Number of trips per shift 15.3 Days worked per month 25.9 Second shift rental achievement 53.9 % The following table presents the carrying value and fair value of financial instruments and the level within the fair value hierarchy in which those measurements are classified at December 31, 2017 and 2016 (dollars in thousands): 2017 2016 Level Carrying Value Fair Value Carrying Value Fair Value Assets: Cash and cash equivalents 1 $ 194,582 $ 194,582 $ 448,313 $ 448,313 Investment securities available for sale 1/2/3 6,680,832 6,680,832 6,073,584 6,073,584 Investment securities held to maturity 3 10,000 10,000 10,000 10,000 Non-marketable equity securities 2 265,989 265,989 284,272 284,272 Loans held for sale 2 34,097 37,847 41,198 45,833 Loans: Covered 3 502,860 922,888 611,942 1,200,291 Non-covered 3 20,768,849 20,759,567 18,630,499 18,713,495 FDIC Indemnification asset 3 295,635 148,356 515,933 256,691 Derivative assets 2 27,627 27,627 50,232 50,232 Liabilities: Demand, savings and money market deposits 2 $ 15,543,637 $ 15,543,637 $ 13,735,248 $ 13,735,248 Time deposits 2 6,334,842 6,324,010 5,755,642 5,759,787 FHLB advances 2 4,771,000 4,774,160 5,239,348 5,244,188 Notes and other borrowings 2 402,830 435,361 402,809 403,733 Derivative liabilities 2 25,373 25,373 61,562 61,562 The following methods and assumptions were used to estimate the fair value of each class of financial instruments, other than those described above: Cash and cash equivalents The carrying value of cash and cash equivalents approximates fair value due to their short-term nature and generally negligible credit risk. Investment securities held to maturity Investment securities held to maturity includes one bond issued by the State of Israel, with fair value obtained from a third party pricing service. Non-marketable equity securities Non-marketable equity securities include FHLB and FRB stock. There is no market for these securities, which can be liquidated only by redemption by the issuer. These securities are valued at par, which has historically represented the redemption price and is therefore considered to approximate fair value. Loans held for sale The fair value of the portion of small business loans guaranteed by U.S. Government agencies being held for sale is estimated using pricing on recent sales of similar loans by the Company in active markets. Covered loans Fair values are estimated based on a discounted cash flow analysis. Estimates of future cash flows incorporate various factors that may include the type of loan and related collateral, estimated collateral values, estimated voluntary prepayment rates, estimated default probability and loss severity given default, whether the interest rate is fixed or variable, term of loan and whether or not the loan is amortizing. The fair values of loans accounted for in pools are estimated on a pool basis. Discount rates for residential loans are based on observable fixed income market data for products with similar credit characteristics. Non-covered loans Fair values of residential loans are estimated using a discounted cash flow analysis with discount rates based on yields at which similar loans are trading in the secondary market, which reflect assumptions about credit risk. Fair values of commercial and consumer loans are estimated using a discounted cash flow analysis with discount rates based on interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. The ALLL related to commercial and consumer loans is considered a reasonable estimate of the required adjustment to fair value to reflect the impact of credit risk. This estimate may not represent an exit value as defined in ASC 820. FDIC indemnification asset The fair value of the FDIC indemnification asset has been estimated using a discounted cash flow technique incorporating assumptions about the timing and amount of future projected cash payments from the FDIC related to the resolution of covered assets. The factors that impact estimates of future cash flows are similar to those impacting estimated cash flows from covered loans. The discount rate is determined by adjusting the risk free rate to incorporate uncertainty in the estimate of the timing and amount of future cash flows and illiquidity. Deposits The fair value of demand deposits, savings accounts and money market deposits is the amount payable on demand at the reporting date. The fair value of time deposits is estimated using a discounted cash flow technique based on rates currently offered for deposits of similar remaining maturities. FHLB advances Fair value is estimated by discounting contractual future cash flows using the current rate at which borrowings with similar terms and remaining maturities could be obtained by the Company. Senior notes Fair value is estimated based on quoted prices of identical securities in less active markets.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company issues off-balance sheet financial instruments to meet the financing needs of its customers. These financial instruments include commitments to fund loans, unfunded commitments under existing lines of credit, and commercial and standby letters of credit. These commitments expose the Company to varying degrees of credit and market risk which are essentially the same as those involved in extending loans to customers, and are subject to the same credit policies used in underwriting loans. Collateral may be obtained based on the Company’s credit evaluation of the counterparty. The Company’s maximum exposure to credit loss is represented by the contractual amount of these commitments. Commitments to fund loans These are agreements to lend funds to customers as long as there is no violation of any condition established in the contract. Commitments to fund loans generally have fixed expiration dates or other termination clauses and may require payment of a fee. Many of these commitments are expected to expire without being funded and, therefore, the total commitment amounts do not necessarily represent future liquidity requirements. Unfunded commitments under lines of credit Unfunded commitments under lines of credit include commercial, commercial real estate, home equity and consumer lines of credit to existing customers. Some of these commitments may mature without being fully funded. Commercial and standby letters of credit Letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. These letters of credit are primarily issued to support trade transactions or guarantee arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. Total lending related commitments outstanding at December 31, 2017 were as follows (in thousands): Commitments to fund loans $ 376,525 Commitments to purchase loans 401,270 Unfunded commitments under lines of credit 2,278,201 Commercial and standby letters of credit 82,854 $ 3,138,850 Legal Proceedings The Company is involved as plaintiff or defendant in various legal actions arising in the normal course of business. In the opinion of management, based upon advice of legal counsel, the likelihood is remote that the impact of these proceedings, either individually or in the aggregate, would be material to the Company’s consolidated financial position, results of operations or cash flows.

Condensed Financial Statements

Condensed Financial Statements of BankUnited, Inc.	12 Months Ended
	Dec. 31, 2017
Condensed Financial Statements [Abstract]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	Condensed Financial Statements of BankUnited, Inc. Condensed financial statements of BankUnited, Inc. are presented below (in thousands): Condensed Balance Sheets December 31, 2017 December 31, 2016 Assets: Cash and cash equivalents $ 131,696 $ 87,718 Investment securities available for sale, at fair value 63,543 78,293 Investment in BankUnited, N.A. 3,239,717 2,652,535 Deferred tax asset, net 9,456 16,738 Other assets 8,462 5,345 Total assets $ 3,452,874 $ 2,840,629 Liabilities and Stockholders' Equity: Notes payable $ 393,725 $ 393,092 Other liabilities 33,087 29,108 Stockholders' equity 3,026,062 2,418,429 Total liabilities and stockholders' equity $ 3,452,874 $ 2,840,629 Condensed Statements of Income Years Ended December 31, 2017 2016 2015 Income: Interest and dividends on investment securities available for sale $ 3,580 $ 4,280 $ 4,866 Service fees from subsidiary 18,787 21,957 17,404 Equity in earnings of subsidiary 639,250 242,874 256,456 Other — — 235 Total 661,617 269,111 278,961 Expense: Interest on borrowings 20,132 20,100 2,457 Employee compensation and benefits 27,032 27,143 22,099 Other 5,047 4,466 4,356 Total 52,211 51,709 28,912 Income before income taxes 609,406 217,402 250,049 Benefit for income taxes (4,867 ) (8,339 ) (1,611 ) Net income $ 614,273 $ 225,741 $ 251,660 Condensed Statements of Cash Flows Years Ended December 31, 2017 2016 2015 Cash flows from operating activities: Net income $ 614,273 $ 225,741 $ 251,660 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (519,250 ) (157,374 ) (176,456 ) Equity based compensation 22,692 18,032 16,027 Other 3,343 7,438 1,878 Net cash provided by operating activities 121,058 93,837 93,109 Cash flows from investing activities: Capital contributions to subsidiary (55,000 ) — (575,000 ) Purchase of investment securities available for sale — (20,150 ) — Proceeds from repayments, sale, maturities and calls of investment securities available for sale 15,000 19,401 46,031 Other (250 ) (3 ) (285 ) Net cash used in investing activities (40,250 ) (752 ) (529,254 ) Cash flows from financing activities: Proceeds from issuance of notes payable — — 392,252 Dividends paid (91,628 ) (89,824 ) (88,981 ) Proceeds from exercise of stock options 62,095 791 35,647 Other (7,297 ) 856 1,593 Net cash provided by (used in) financing activities (36,830 ) (88,177 ) 340,511 Net increase (decrease) in cash and cash equivalents 43,978 4,908 (95,634 ) Cash and cash equivalents, beginning of period 87,718 82,810 178,444 Cash and cash equivalents, end of period $ 131,696 $ 87,718 $ 82,810 Supplemental schedule of non-cash investing and financing activities: Dividends declared, not paid $ 23,055 $ 22,510 $ 22,380 Dividends received by BankUnited, Inc. from the Bank totaled $ 120 million , $85.5 million and $80 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively.

Quarterly Financial Information

Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Financial Information (Unaudited) Financial information by quarter for the years ended December 31, 2017 and 2016 follows (in thousands, except per share data): 2017 Fourth Quarter Third Quarter Second Quarter First Quarter Total Interest income $ 312,645 $ 309,443 $ 298,835 $ 283,538 $ 1,204,461 Interest expense 73,819 68,179 59,246 52,945 254,189 Net interest income before provision for loan losses 238,826 241,264 239,589 230,593 950,272 Provision for loan losses 5,174 37,854 13,619 12,100 68,747 Net interest income after provision for loan losses 233,652 203,410 225,970 218,493 881,525 Non-interest income 46,541 53,326 29,893 28,144 157,904 Non-interest expense 161,271 156,705 160,435 156,557 634,968 Income before income taxes 118,922 100,031 95,428 90,080 404,461 Provision (benefit) for income taxes (298,872 ) 32,252 29,021 27,787 (209,812 ) Net income $ 417,794 $ 67,779 $ 66,407 $ 62,293 $ 614,273 Earnings per common share, basic $ 3.80 $ 0.62 $ 0.60 $ 0.57 $ 5.60 Earnings per common share, diluted $ 3.79 $ 0.62 $ 0.60 $ 0.57 $ 5.58 2016 Fourth Quarter Third Quarter Second Quarter First Quarter Total Interest income $ 277,965 $ 269,981 $ 260,464 $ 250,807 $ 1,059,217 Interest expense 50,466 48,246 46,154 43,966 188,832 Net interest income before provision for loan losses 227,499 221,735 214,310 206,841 870,385 Provision for loan losses 8,462 24,408 14,333 3,708 50,911 Net interest income after provision for loan losses 219,037 197,327 199,977 203,133 819,474 Non-interest income 29,287 25,075 28,857 23,198 106,417 Non-interest expense 156,223 148,004 144,112 142,108 590,447 Income before income taxes 92,101 74,398 84,722 84,223 335,444 Provision (benefit) for income taxes 28,807 23,550 27,997 29,349 109,703 Net income $ 63,294 $ 50,848 $ 56,725 $ 54,874 $ 225,741 Earnings per common share, basic $ 0.59 $ 0.47 $ 0.53 $ 0.51 $ 2.11 Earnings per common share, diluted $ 0.59 $ 0.47 $ 0.52 $ 0.51 $ 2.09 Earnings for the fourth quarter 2017 benefited from a discrete income tax benefit of $327.9 million . See Note 11 to the consolidated financial statements for more information about the discrete income tax benefits.

Basis of Presentation and Sum27

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting [Text Block]	The consolidated financial statements have been prepared in accordance with GAAP and prevailing practices in the banking industry. The Company has a single reportable segment.
Use of Estimates, Policy [Policy Text Block]	Accounting Estimates In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, and expenses and disclosures of contingent assets and liabilities. Actual results could differ significantly from these estimates. Significant estimates include the ALLL, the amount and timing of expected cash flows from covered assets and the FDIC indemnification asset, and the fair values of investment securities and other financial instruments. Management has used information provided by third party valuation specialists to assist in the determination of the fair values of investment securities.
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The consolidated financial statements include the accounts of BankUnited, Inc. and its wholly-owned subsidiary. All significant intercompany balances and transactions have been eliminated in consolidation. VIEs are consolidated if the Company is the primary beneficiary; i.e., has (i) the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and (ii) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company has variable interests in affordable housing limited partnerships that are not required to be consolidated because the Company is not the primary beneficiary.
Fair Value Measurement, Policy [Policy Text Block]	Fair Value Measurements Certain of the Company's assets and liabilities are reflected in the financial statements at fair value on either a recurring or non-recurring basis. Investment securities available for sale, servicing rights and derivative instruments are measured at fair value on a recurring basis. Assets measured at fair value or fair value less cost to sell on a non-recurring basis may include collateral dependent impaired loans, OREO and other repossessed assets, loans held for sale, goodwill, impaired long-lived assets and assets acquired and liabilities assumed in business combinations. These non-recurring fair value measurements typically involve the application of acquisition accounting, lower-of-cost-or-market accounting or the measurement of impairment of certain assets. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. GAAP establishes a hierarchy that prioritizes inputs used to determine fair value measurements into three levels based on the observability and transparency of the inputs: • Level 1 inputs are unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities. • Level 2 inputs are observable inputs other than level 1 inputs, including quoted prices for similar assets and liabilities, quoted prices for identical assets and liabilities in less active markets and other inputs that can be corroborated by observable market data. • Level 3 inputs are unobservable inputs supported by limited or no market activity or data and inputs requiring significant management judgment or estimation. The fair value hierarchy requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs in estimating fair value. Unobservable inputs are utilized in determining fair value measurements only to the extent that observable inputs are unavailable. The need to use unobservable inputs generally results from a lack of market liquidity and diminished observability of actual trades or assumptions that would otherwise be available to value a particular asset or liability. Transfers between levels of the fair value hierarchy are recorded as of the end of the reporting period.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents include cash and due from banks, both interest bearing and non-interest bearing, including amounts on deposit at the Federal Reserve Bank, and federal funds sold. Cash equivalents have original maturities of three months or less. For purposes of reporting cash flows, cash receipts and payments pertaining to FHLB advances with original maturities of three months or less are reported net.
Marketable Securities, Available-for-sale Securities, Policy [Policy Text Block]	Investment Securities Debt securities that the Company has the positive intent and ability to hold to maturity are classified as held to maturity and reported at amortized cost. Debt securities that the Company may not have the intent to hold to maturity and marketable equity securities are classified as available for sale at the time of acquisition and carried at fair value with unrealized gains and losses, net of tax, excluded from earnings and reported in AOCI, a separate component of stockholders' equity. Securities classified as available for sale may be used as part of the Company's asset/liability management strategy and may be sold in response to liquidity needs, regulatory changes, changes in interest rates, prepayment risk or other market factors. The Company does not maintain a trading portfolio. Purchase premiums and discounts on debt securities are amortized as adjustments to yield over the expected lives of the securities, using the level yield method. Premiums are amortized to the call date if the call is considered to be clearly and closely related to the host contract. Realized gains and losses from sales of securities are recorded on the trade date and are determined using the specific identification method. The Company reviews investment securities for OTTI at least quarterly. An investment security is impaired if its fair value is lower than its amortized cost basis. The Company considers many factors in determining whether a decline in fair value below amortized cost represents OTTI, including, but not limited to: • the Company's intent to hold the security until maturity or for a period of time sufficient for a recovery in value; • whether it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis; • the length of time and extent to which fair value has been less than amortized cost; • adverse changes in expected cash flows; • collateral values and performance; • the payment structure of the security including levels of subordination or over-collateralization; • changes in the economic or regulatory environment; • the general market condition of the geographic area or industry of the issuer; • the issuer's financial condition, performance and business prospects; and • changes in credit ratings. The relative importance assigned to each of these factors varies depending on the facts and circumstances pertinent to the individual security being evaluated. The Company recognizes OTTI of a debt security for which there has been a decline in fair value below amortized cost if (i) management intends to sell the security, (ii) it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, or (iii) the Company does not expect to recover the entire amortized cost basis of the security. If the Company intends to sell the security, or if it is more likely than not it will be required to sell the security before recovery, an OTTI write-down is recognized in earnings equal to the entire difference between the amortized cost basis and fair value of the security. Otherwise, the amount by which amortized cost exceeds the fair value of a debt security that is considered to be other-than-temporarily impaired is separated into a component representing the credit loss, which is recognized in earnings, and a component related to all other factors, which is recognized in other comprehensive income. The measurement of the credit loss component is equal to the difference between the debt security's amortized cost basis and the present value of its expected future cash flows discounted at the security's effective yield. The evaluation of OTTI of marketable equity securities focuses on whether evidence supports recovery of the unrealized loss within a timeframe consistent with temporary impairment. The entire amount by which cost basis exceeds the fair value of an equity security that is considered to be other-than-temporarily impaired is recognized in earnings.
Nonmarketable Equity Securities [Policy Text Block]	Non-marketable Equity Securities The Bank, as a member of the FRB system and the FHLB, is required to maintain investments in the stock of the FRB and FHLB. No market exists for this stock, and the investment can be liquidated only through redemption by the respective institutions, at the discretion of and subject to conditions imposed by those institutions. The stock has no readily determinable fair value and is carried at cost. Historically, stock redemptions have been at par value, which equals the Company's carrying value. The Company monitors its investment in FHLB stock for impairment through review of recent financial results of the FHLB, including capital adequacy and liquidity position, dividend payment history, redemption history and information from credit agencies. The Company has not identified any indicators of impairment of FHLB stock.
Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block]	Loans Held for Sale The guaranteed portion of SBA and USDA loans originated with the intent to sell are carried at the lower of cost or fair value, determined in the aggregate. A valuation allowance is established through a charge to earnings if the aggregate fair value of such loans is lower than their cost. Gains or losses recognized upon sale are determined on the specific identification basis. Loans not originated or otherwise acquired with the intent to sell are transferred into the held for sale classification at the lower of carrying amount or fair value when they are specifically identified for sale and a formal plan exists to sell them. Acquired credit impaired loans accounted for in pools are removed from the pools at their carrying amounts when they are sold.
Finance, Loan and Lease Receivables, Held-for-investment, Policy [Policy Text Block]	Loans The Company's loan portfolio contains 1-4 single family residential first mortgages, home equity loans and lines of credit, consumer, multi-family, owner and non-owner occupied commercial real estate, construction and land, and commercial and industrial loans, mortgage warehouse lines of credit and direct financing leases. The Company segregates its loan portfolio between covered and non-covered loans. Covered loans are loans acquired from the FDIC in the FSB Acquisition that are covered under the Single Family Shared-Loss Agreement. Covered loans are further segregated between ACI loans and non-ACI loans. Non-covered Loans Non-covered loans, other than non-covered ACI loans, are carried at UPB, net of premiums, discounts, unearned income, deferred loan origination fees and costs, and the ALLL. Interest income on these loans is accrued based on the principal amount outstanding. Non-refundable loan origination fees, net of direct costs of originating or acquiring loans, as well as purchase premiums and discounts, are deferred and recognized as adjustments to yield over the contractual lives of the related loans using the level yield method. Direct Financing Leases Direct financing leases are carried at the aggregate of lease payments receivable and estimated residual value of the leased property, if applicable, less unearned income. Interest income on direct financing leases is recognized over the term of the leases to achieve a constant periodic rate of return on the outstanding investment. Initial direct costs are deferred and amortized over the lease term as a reduction to interest income using the effective interest method.
ACI Loans [Policy Text Block]	ACI Loans ACI loans, all of which were acquired in the FSB Acquisition and the substantial majority of which are covered under the Single Family Shared-Loss Agreement, are those for which, at acquisition, management determined it probable that the Company would be unable to collect all contractual principal and interest payments due. These loans were recorded at estimated fair value at acquisition, measured as the present value of all cash flows expected to be received, discounted at an appropriately risk-adjusted discount rate. Initial cash flow expectations incorporated significant assumptions regarding prepayment rates, frequency of default and loss severity. The difference between total contractually required payments on ACI loans and the cash flows expected to be received represents non-accretable difference. The excess of all cash flows expected to be received over the Company's recorded investment in the loans represents accretable yield and is recognized as interest income on a level-yield basis over the expected life of the loans. The Company aggregated ACI 1-4 single family residential mortgage loans and home equity loans and lines of credit with similar risk characteristics into homogenous pools at acquisition. A composite interest rate and composite expectations of future cash flows are used in accounting for each pool. These loans were aggregated into pools based on the following characteristics: • delinquency status; • product type, in particular, amortizing as opposed to option ARMs; • loan-to-value ratio; and • borrower FICO score. Loans that do not have similar risk characteristics, primarily commercial and commercial real estate loans, are accounted for on an individual loan basis using interest rates and expectations of cash flows for each loan. The Company is required to develop reasonable expectations about the timing and amount of cash flows to be collected related to ACI loans and to continue to update those estimates over the lives of the loans. Expected cash flows from ACI loans are updated quarterly. If it is probable that the Company will be unable to collect all the cash flows expected from a loan or pool at acquisition plus additional cash flows expected to be collected arising from changes in estimates after acquisition, the loan or pool is considered impaired and a valuation allowance is established by a charge to the provision for loan losses. If there is an increase in expected cash flows from a loan or pool, the Company first reduces any valuation allowance previously established by the amount of the increase in the present value of expected cash flows, and then recalculates the amount of accretable yield for that loan or pool. The adjustment of accretable yield due to an increase in expected cash flows, as well as changes in expected cash flows due to changes in interest rate indices and changes in prepayment assumptions is accounted for prospectively as a change in yield. Additional cash flows expected to be collected are transferred from non-accretable difference to accretable yield and the amount of periodic accretion is adjusted accordingly over the remaining life of the loan or pool. The Company may resolve an ACI loan either through a sale of the loan, by working with the customer and obtaining partial or full repayment, by short sale of the collateral, or by foreclosure. When a loan accounted for in a pool is resolved, it is removed from the pool at its allocated carrying amount. In the event of a sale of the loan, the Company recognizes a gain or loss on sale based on the difference between the sales proceeds and the carrying amount of the loan. For loans resolved through pre-payment or short sale of the collateral, the Company recognizes the difference between the amount of the payment received and the carrying amount of the loan in the income statement line item "Income from resolution of covered assets, net". For loans resolved through foreclosure, the difference between the fair value of the collateral obtained through foreclosure less estimated cost to sell and the carrying amount of the loan is recognized in the income statement line item "Income from resolution of covered assets, net". Any remaining accretable discount related to loans not accounted for in pools that are resolved by full or partial pre-payment, short sale or foreclosure is recognized in interest income at the time of resolution, to the extent collected. Payments received earlier than expected or in excess of expected cash flows from sales or other resolutions may result in the carrying value of a pool being reduced to zero even though outstanding contractual balances and expected cash flows remain related to loans in the pool. Once the carrying value of a pool is reduced to zero, any future proceeds, which may include cash or real estate acquired in foreclosure, from the remaining loans, representing further realization of accretable yield, are recognized as interest income upon receipt.
Non-ACI Loans [Policy Text Block]	Covered Non-ACI Loans Loans acquired in the FSB Acquisition without evidence of deterioration in credit quality since origination were initially recorded at estimated fair value on the acquisition date. Non-ACI 1-4 single family residential mortgage loans and home equity loans and lines of credit with similar risk characteristics were aggregated into pools for accounting purposes at acquisition. Non-ACI loans are carried at the principal amount outstanding, adjusted for unamortized acquisition date fair value adjustments and the ALLL. Interest income is accrued based on the UPB and, with the exception of home equity loans and lines of credit, acquisition date fair value adjustments are amortized using the level-yield method over the expected lives of the related loans. For non-ACI 1-4 family residential mortgage loans accounted for in pools, prepayment estimates are used in determining the periodic amortization of acquisition date fair value adjustments. Acquisition date fair value adjustments related to revolving home equity loans and lines of credit are amortized on a straight-line basis.
Loans and Leases Receivable, Nonaccrual Loan and Lease Status, Policy [Policy Text Block]	Non-accrual Loans Commercial loans, other than ACI loans, are placed on non-accrual status when (i) management has determined that full repayment of all contractual principal and interest is in doubt, or (ii) the loan is past due 90 days or more as to principal or interest unless the loan is well secured and in the process of collection. Given continued unstable conditions in the taxi industry, continued declines in ridership, and the relatively long amortization periods for most of these loans, there exists an increasing level of uncertainty with respect to the Company's ability to collect all contractual principal and interest on taxi medallion loans. Therefore, all taxi medallion loans have been placed on non-accrual status. Residential and consumer loans, other than ACI loans, are generally placed on non-accrual status when 90 days of interest is due and unpaid. When a loan is placed on non-accrual status, uncollected interest accrued is reversed and charged to interest income. Payments received on nonaccrual commercial loans are applied as a reduction of principal. Interest payments are recognized as income on a cash basis on nonaccrual residential loans. Commercial loans are returned to accrual status only after all past due principal and interest has been collected and full repayment of remaining contractual principal and interest is reasonably assured. Residential and consumer loans are returned to accrual status when there is no longer 90 days of interest due and unpaid. Past due status of loans is determined based on the contractual next payment due date. Loans less than 30 days past due are reported as current. Contractually delinquent ACI loans are not classified as non-accrual as long as discount continues to be accreted on the loans or pools.
Impaired Financing Receivable, Policy [Policy Text Block]	Impaired Loans Loans, other than ACI loans, are considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due, according to the contractual terms of the loan agreements. Commercial relationships with committed balances greater than or equal to $1.0 million that have internal risk ratings of substandard or doubtful and are on non-accrual status, as well as loans that have been modified in TDRs, are individually evaluated for impairment. Other commercial relationships on non-accrual status with committed balances under $1.0 million may also be evaluated individually for impairment at management's discretion. All loans secured by taxi medallions are individually evaluated for impairment. The likelihood of loss related to loans assigned internal risk ratings of substandard or doubtful is considered elevated due to their identified credit weaknesses. Factors considered by management in evaluating impairment include payment status, financial condition of the borrower, collateral value, and other factors impacting the probability of collecting scheduled principal and interest payments when due. An ACI pool or loan is considered to be impaired when it is probable that the Company will be unable to collect all the cash flows expected at acquisition, plus additional cash flows expected to be collected arising from changes in estimates after acquisition. 1-4 single family residential and home equity ACI loans accounted for in pools are evaluated collectively for impairment on a pool by pool basis based on expected pool cash flows. Commercial ACI loans are individually evaluated for impairment based on expected cash flows from the individual loans. Discount continues to be accreted on ACI loans or pools as long as there are expected future cash flows in excess of the current carrying amount of the loans or pools.
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	Troubled Debt Restructurings In certain situations due to economic or legal reasons related to a borrower's financial difficulties, the Company may grant a concession to the borrower for other than an insignificant period of time that it would not otherwise consider. At that time, except for ACI loans accounted for in pools, the related loan is classified as a TDR and considered impaired. The concessions granted may include rate reductions, principal forgiveness, payment forbearance, extensions of maturity at rates of interest below that commensurate with the risk profile of the loans, modification of payment terms and other actions intended to minimize economic loss. A TDR is generally placed on non-accrual status at the time of the modification unless the borrower was performing prior to the restructuring. Modified ACI loans accounted for in pools are not accounted for as TDRs, are not separated from the pools and are not classified as impaired loans.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for Loan and Lease Losses The ALLL represents the amount considered adequate by management to absorb probable losses inherent in the loan portfolio at the balance sheet date. The ALLL consists of both specific and general components. The ALLL is established as losses are estimated to have occurred through a provision charged to earnings. Individual loans are charged off against the ALLL when management determines them to be uncollectible. An assessment of collateral value is made at no later than 120 days delinquency for non-covered open- and closed-end loans secured by residential real estate; any outstanding loan balance in excess of fair value less cost to sell is charged off at no later than 180 days delinquency. Additionally, any outstanding balance in excess of fair value of collateral less cost to sell is charged off (i) within 60 days of receipt of notification of filing from the bankruptcy court, (ii) within 60 days of determination of loss if all borrowers are deceased or (iii) within 90 days of discovery of fraudulent activity. Covered non-ACI loans secured by residential real estate are generally charged off at final resolution which is consistent with the terms of the Single Family Shared-Loss Agreement. Consumer loans are typically charged off at 120 days delinquency. Commercial loans are charged off when management deems them to be uncollectible. Subsequent recoveries are credited to the ALLL. Non-covered Loans The non-covered residential and home equity portfolio segments have not yet developed an observable loss trend. Due to several factors, there is a lack of similarity between the risk characteristics of non-covered loans and covered loans in the residential and home equity portfolios. Therefore, management does not believe it is appropriate to use the historical performance of the covered residential loans as a basis for calculating the ALLL applicable to the non-covered loans. The ALLL for non-covered 1-4 single family residential loans is based on average annual loss rates on prime residential mortgage securitizations issued between 2003 and 2008. Loans included in these securitizations have credit characteristics, such as LTV and FICO scores, considered by management to be comparable to characteristics of loans in the non-covered 1-4 single family residential portfolio. The ALLL for non-covered home equity and other consumer loans is based on peer group average historical loss rates. The credit quality of loans in the residential portfolio segment may be impacted by fluctuations in home values, unemployment, general economic conditions, borrowers' financial circumstances and fluctuations in interest rates. The credit quality of commercial loans is impacted by general and industry specific economic conditions and other factors that may influence debt service coverage generated by the borrowers' businesses as well as fluctuations in the value of real estate and other collateral. For loans evaluated individually for impairment and determined to be impaired, a specific allowance is established based on the present value of expected cash flows discounted at the loan's effective interest rate, the estimated fair value of the loan, or for collateral dependent loans, the estimated fair value of collateral less costs to sell. Commercial loans, other than ACI commercial loans, not individually determined to be impaired are grouped based on common risk characteristics. Quantitative loss factors for pass rated commercial loans in portfolio segments that have not yet developed an observable loss trend are based primarily on peer group average historical loss rates and the Bank's internal credit risk rating system. Quantitative loss factors for the Bridge portfolios, small business loans and mortgage warehouse loans are based on the Company's average historical net charge-off rates. The quantitative loss factor applied to the non-guaranteed portion of SBA loans is based on average historical charge-off rates published by the SBA. The quantitative loss factor for municipal loans and direct finance leases is based on the portfolio's external ratings and Moody's historical transition matrix. Quantitative loss rates are generally based on a four -quarter loss emergence period and a 16 -quarter loss experience period; for municipal loans and leases, a 12 -quarter loss emergence period is used. The source of quantitative loss factors for the Bridge portfolios, municipal loans and leases, SBA loans, and mortgage warehouse loans was revised in 2017, with no material impact to the ALLL. Where applicable, the peer group used to calculate average annual historical net charge-off rates used in estimating the Bank's general reserves is a group of 27 banks made up of the banks included in the OCC Midsize Bank Group and two additional banks in the New York region that management believes to be comparable based on size and nature of lending operations. The quantitative loss factor for loans rated special mention is based on average annual probability of default and implied severity, derived from internal and external data. Loss factors for substandard and doubtful loans that are not individually evaluated for impairment are determined by using default frequency and severity information applied at the loan level. Estimated default frequencies and severities are based on available industry data. Qualitative adjustments are made to the ALLL when, based on management's judgment and experience, there are internal or external factors impacting incurred losses not taken into account by the quantitative calculations. Management has categorized potential qualitative adjustments into the following categories: • Portfolio performance trends, including trends in and the levels of delinquencies, non-performing loans and classified loans; • Changes in the nature of the portfolio and terms of the loans, specifically including the volume and nature of policy and procedural exceptions; • Portfolio growth trends; • Changes in lending policies and procedures, including credit and underwriting guidelines; • Economic factors, including unemployment rates and GDP growth rates; • Changes in the value of underlying collateral; • Quality of risk ratings, as evaluated by our independent credit review function; • Credit concentrations; • Changes in and experience levels of credit administration management and staff; and • Other factors identified by management that may impact the level of losses inherent in the portfolio, including but not limited to competition, legal and regulatory requirements and unusual events. Covered Non-ACI Loans Calculated loss frequency and severity percentages are applied to the UPB of non-ACI 1-4 single family residential mortgages and home equity loans and lines of credit to calculate the ALLL. Based on an analysis of historical portfolio performance, OREO and short sale data, and other internal and external factors, management has concluded that historical performance by portfolio class is the best indicator of incurred loss for the non-ACI 1-4 single family residential and home equity portfolio classes. For each of these portfolio classes, a quarterly roll rate matrix is used to measure the rate at which loans move from one delinquency bucket to the next during a given quarter. An average 16-quarter roll rate matrix is used to estimate the amount within each delinquency bucket expected to roll to 120 + days delinquent within a four quarter loss emergence period. Loss severity given default is estimated based on internal data about short sales and OREO sales. The ALLL calculation incorporates a 100% loss severity assumption for home equity loans and lines of credit projected to roll to 120 days delinquency. Substantially all non-ACI home equity loans and lines of credit were sold in the fourth quarter of 2017. ACI Loans A specific valuation allowance related to an ACI loan or pool is established when quarterly evaluations of expected cash flows indicate it is probable that the Company will be unable to collect all of the cash flows expected at acquisition plus any additional cash flows expected to be collected arising from changes in estimate after acquisition. The amount of any necessary valuation allowance is measured by comparing the carrying value of the loan or pool to the updated net present value of expected cash flows for the loan or pool. In calculating the present value of expected cash flows for this purpose, changes in cash flows related to credit related factors are isolated from those related to changes in interest rate indices or prepayment assumptions. Alternatively, an improvement in the expected cash flows related to ACI loans results in a reduction of any previously established specific allowance with a corresponding credit to the provision for loan losses. A charge-off is taken for an individual ACI commercial loan when it is deemed probable that the loan will be resolved for an amount less than its carrying value. Expected cash flows are estimated on a pool basis for ACI 1-4 single family residential and home equity loans. The analysis of expected pool cash flows incorporates updated pool level expected prepayment rate, default rate, delinquency level and loss severity given default assumptions. Prepayment, delinquency and default curves are derived primarily from roll rates generated from the historical performance of the portfolio over the immediately preceding four quarters. Loss severity given default for loans not projected to resolve through sale is generated from the historical performance of the portfolio over the immediately preceding four quarters, while loss severity from loan sales is generated from historical performance over the immediately preceding twelve quarters. Estimates of default probability and loss severity also incorporate updated LTV ratios, at the loan level, based on Case-Shiller Home Price Indices for the relevant MSA. Costs and fees represent an additional component of loss on default and are projected using the Bank's actual experience over the preceding twelve quarters. The primary assumptions underlying estimates of expected cash flows for commercial ACI loans are default probability and severity of loss given default. Generally, updated cash flow assumptions are based primarily on net realizable value analyses prepared at the individual loan level. These analyses incorporate information about loan performance, collateral values, the financial condition of the borrower and other available information that may impact sources of repayment. Reserve for Unfunded Commitments The reserve for unfunded commitments represents the estimated probable losses related to unfunded lending commitments. The reserve is calculated in a manner similar to the general reserve for non-covered loans, while also considering the timing and likelihood that the available credit will be utilized as well as the exposure upon default. The reserve for unfunded commitments is presented within other liabilities on the consolidated balance sheets, distinct from the ALLL, and adjustments to the reserve for unfunded commitments are included in other non-interest expense in the consolidated statements of income.
FDIC Indemnification Asset [Policy Text Block]	FDIC Indemnification Asset The FDIC indemnification asset was initially recorded at the time of the FSB Acquisition at fair value, measured as the present value of the estimated cash payments expected from the FDIC for probable losses on covered assets. The FDIC indemnification asset is measured separately from the related covered assets. It is not contractually embedded in the covered assets and it is not transferable with the covered assets should the Company choose to dispose of them. Impairment of expected cash flows from covered assets results in an increase in cash flows expected to be collected from the FDIC. These increased expected cash flows from the FDIC are recognized as increases in the FDIC indemnification asset and as non-interest income in the same period that the impairment of the covered assets is recognized in the provision for loan losses. Increases in expected cash flows from covered assets result in decreases in cash flows expected to be collected from the FDIC. These decreases in expected cash flows from the FDIC are recognized immediately in earnings to the extent that they relate to a reversal of a previously recorded valuation allowance related to the covered assets. Any remaining decreases in cash flows expected to be collected from the FDIC are recognized prospectively through an adjustment of the rate of accretion or amortization on the FDIC indemnification asset, consistent with the approach taken to recognize increases in expected cash flows on the covered assets. Amortization of the FDIC indemnification asset results from circumstances in which, due to improvement in expected cash flows from the covered assets, expected cash flows from the FDIC are less than the carrying value of the FDIC indemnification asset. Accretion or amortization of the FDIC indemnification asset is recognized in earnings using the effective interest method over the period during which cash flows from the FDIC are expected to be collected, which is limited to the lesser of the contractual term of the indemnification agreement and the remaining life of the indemnified assets. Gains and losses from resolution of ACI loans are included in the income statement line item "Income from resolution of covered assets, net." These gains and losses represent the difference between the expected losses from ACI loans and consideration actually received in satisfaction of such loans that were resolved either by payment in full, foreclosure or short sale. The Company may also realize gains or losses on the sale or impairment of covered loans or covered OREO. When the Company recognizes gains or losses related to the resolution, sale or impairment of covered assets in earnings, corresponding changes in the estimated amount recoverable from the FDIC under the Loss Sharing Agreements are reflected in the consolidated financial statements as increases or decreases in the FDIC indemnification asset and in the consolidated statement of income line item " Net loss on FDIC indemnification ."
Bank Owned Life Insurance [Policy Text Block]	Bank Owned Life Insurance Bank owned life insurance is carried at the amount that could be realized under the contract at the balance sheet date, which is typically cash surrender value. Changes in cash surrender value are recorded in non-interest income.
Lessor, Leases [Policy Text Block]	Equipment Under Operating Lease Equipment under operating lease is carried at cost less accumulated depreciation and is depreciated to estimated residual value using the straight-line method over the lease term. Estimated residual values are re-evaluated at least annually, based primarily on current residual value appraisals. Rental revenue is recognized on a straight-line basis over the contractual term of the lease. A review for impairment of equipment under operating lease is performed at least annually or when events or changes in circumstances indicate that the carrying amount of long-lived assets may not be recoverable. Impairment of assets is determined by comparing the carrying amount to future undiscounted net cash flows expected to be generated. If an asset is impaired, the measure of impairment is the amount by which the carrying amount exceeds the fair value of the asset.
Goodwill and Intangible Assets, Policy [Policy Text Block]	Goodwill Goodwill of $78 million at both December 31, 2017 and 2016 represents the excess of consideration transferred in business combinations over the fair value of net tangible and identifiable intangible assets acquired. Goodwill is not amortized, but is tested for impairment annually or more frequently if events or circumstances indicate that impairment may have occurred. The Company performs its annual goodwill impairment test in the third fiscal quarter. The Company has a single reporting unit. The impairment test compares the estimated fair value of the reporting unit to its carrying amount. If the fair value of the reporting unit exceeds its carrying amount, no impairment is indicated. If the fair value of the reporting unit is less than its carrying amount, impairment of goodwill is measured as the excess of the carrying amount over fair value. The estimated fair value of the reporting unit is based on the market capitalization of the Company's common stock. The estimated fair value of the reporting unit at each impairment testing date substantially exceeded its carrying amount; therefore, no impairment of goodwill was indicated.
Finance, Loan and Lease Receivables, Held for Investments, Foreclosed Assets Policy [Policy Text Block]	Foreclosed Property and Repossessed Assets Foreclosed property and repossessed assets consists of real estate assets acquired through, or in lieu of, loan foreclosure and personal property acquired through repossession. Such assets are included in other assets in the accompanying consolidated balance sheets. These assets are held for sale and are initially recorded at estimated fair value less costs to sell, establishing a new cost basis. Subsequent to acquisition, periodic valuations are performed and the assets are carried at the lower of the carrying amount at the date of acquisition or estimated fair value less cost to sell. Significant property improvements are capitalized to the extent that the resulting carrying value does not exceed fair value less cost to sell. Legal fees, maintenance, taxes, insurance and other direct costs of holding and maintaining these assets are expensed as incurred.
Property, Plant and Equipment, Policy [Policy Text Block]	Premises and Equipment Premises and equipment are carried at cost less accumulated depreciation and amortization and are included in other assets in the accompanying consolidated balance sheets. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. The lives of improvements to existing buildings are based on the lesser of the estimated remaining lives of the buildings or the estimated useful lives of the improvements. Leasehold improvements are amortized over the shorter of the expected terms of the leases at inception, considering options to extend that are reasonably assured, or their useful lives. Direct costs of materials and services associated with developing or obtaining and implementing internal use computer software incurred during the application and development stage are capitalized and amortized over the estimated useful lives of the software. The estimated useful lives of premises and equipment are as follows: • buildings and improvements - 30 years ; • leasehold improvements - 5 to 20 years ; • furniture, fixtures and equipment - 5 to 7 years ; • computer equipment - 3 to 5 years ; and • software and software licensing rights - 3 to 5 years .
Transfers and Servicing of Financial Assets, Servicing of Financial Assets, Policy [Policy Text Block]	Loan Servicing Rights Loan servicing rights are measured at fair value, with changes in fair value subsequent to acquisition recognized in earnings. Prior to January 1, 2016, residential MSRs were measured using the amortization method subsequent to acquisition. This change in accounting policy had no impact on opening retained earnings at January 1, 2016. Loan servicing rights are included in other assets in the accompanying consolidated balance sheets. Servicing fee income is recorded net of changes in fair value in other non-interest income. Neither the loan servicing rights nor related income have had a material impact on the Company's financial statements to date.
Investments in Affordable Housing Limited Partnerships [Policy Text Block]	Investments in Affordable Housing Limited Partnerships The Company has acquired investments in limited partnerships that manage or invest in qualified affordable housing projects and provide the Company with low-income housing tax credits and other tax benefits. These investments are included in other assets in the accompanying consolidated balance sheets. The Company accounts for investments in qualified affordable housing projects using the proportional amortization method if certain criteria are met. Under the proportional amortization method, the initial cost of the investment is amortized in proportion to the tax credits and other tax benefits received and the amortization is recognized in the income statement as a component of income tax expense. The investments are evaluated for impairment when events or changes in circumstances indicate that it is more likely than not that the carrying amount of the investment will not be realized.
Income Tax, Policy [Policy Text Block]	Income Taxes The Company accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities using enacted tax rates in effect for periods in which the differences are expected to reverse. The effect of changes in tax rates on deferred tax assets and liabilities are recognized in income in the period that includes the enactment date. A valuation allowance is established for deferred tax assets when management determines that it is more likely than not that some portion or all of a deferred tax asset will not be realized. In making such determinations, the Company considers all available positive and negative evidence that may impact the realization of deferred tax assets. These considerations include the amount of taxable income generated in statutory carryback periods, future reversals of existing taxable temporary differences, projected future taxable income and available tax planning strategies. The Company recognizes tax benefits from uncertain tax positions when it is more likely than not that the related tax positions will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits of the tax positions. An uncertain tax position is a position taken in a previously filed tax return or a position expected to be taken in a future tax return that is not based on clear and unambiguous tax law. The Company measures tax benefits related to uncertain tax positions based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. If the initial assessment fails to result in recognition of a tax benefit, the Company subsequently recognizes a tax benefit if (i) there are changes in tax law or case law that raise the likelihood of prevailing on the technical merits of the position to more-likely-than-not, (ii) the statute of limitations expires, or (iii) there is a completion of an examination resulting in a settlement of that tax year or position with the appropriate agency. The Company recognizes interest and penalties related to uncertain tax positions, as well as interest income or expense related to tax settlements, in the provision for income taxes.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Equity Based Compensation The Company periodically grants unvested or restricted shares of common stock and other share-based awards to key employees. For equity classified awards, compensation cost is measured based on the estimated fair value of the awards at the grant date and is recognized in earnings on a straight-line basis over the requisite service period for each award. Liability-classified awards are remeasured each reporting period at fair value until the award is settled, and compensation cost is recognized in earnings on a straight-line basis over the requisite service period for each award, adjusted for changes in fair value each reporting period. Compensation cost related to awards that embody performance conditions is recognized when it is probable that the performance conditions will be achieved. The number of awards expected to vest is estimated in determining the amount of compensation cost to be recognized related to share-based payment transactions. The fair value of unvested shares is based on the closing market price of the Company's common stock at the date of grant. Market conditions embedded in awards are reflected in the grant-date fair value of the awards.
Derivatives, Policy [Policy Text Block]	Derivative Financial Instruments and Hedging Activities Interest rate derivative contracts The Company uses interest rate derivative contracts, such as swaps, caps, floors and collars, in the normal course of business to meet the financial needs of its customers and to manage exposure to changes in interest rates. Interest rate contracts are recorded as assets or liabilities in the consolidated balance sheets at fair value. Interest rate swaps that are used as a risk management tool to hedge the Company's exposure to changes in interest rates have been designated as cash flow hedging instruments. The gain or loss resulting from changes in the fair value of interest rate swaps designated and qualifying as cash flow hedging instruments is initially reported as a component of other comprehensive income and subsequently reclassified into earnings in the same period in which the hedged transaction affects earnings. The Company discontinues hedge accounting prospectively when it is determined that the derivative is no longer effective in offsetting changes in the cash flows of the hedged item, the derivative expires or is sold, terminated, or exercised, management determines that the designation of the derivative as a hedging instrument is no longer appropriate or the occurrence of the forecasted transaction is no longer probable. When hedge accounting is discontinued, any subsequent changes in fair value of the derivative are recognized in earnings. The cumulative unrealized gain or loss related to a discontinued cash flow hedge continues to be reported in AOCI and is subsequently reclassified into earnings in the same period in which the hedged transaction affects earnings, unless it is probable that the forecasted transaction will not occur by the end of the originally specified time period, in which case the cumulative unrealized gain or loss reported in AOCI is reclassified into earnings immediately. Cash flows resulting from derivative financial instruments that are accounted for as hedges are classified in the cash flow statement in the same category as the cash flows from the hedged items. Changes in the fair value of interest rate contracts not designated as, or not qualifying as, hedging instruments are recognized currently in earnings.
Transfers and Servicing of Financial Assets, Transfers of Financial Assets, Financings, Policy [Policy Text Block]	Transfers of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. A gain or loss is recognized in earnings upon completion of the sale based on the difference between the sales proceeds and the carrying value of the assets. Control over the transferred assets is deemed to have been surrendered when: (i) the assets have been legally isolated from the Company, (ii) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (iii) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity or the ability to unilaterally cause the holder to return specific assets.
Advertising Costs, Policy [Policy Text Block]	Advertising Costs Advertising costs are expensed as incurred.
Earnings Per Share, Policy [Policy Text Block]	Earnings per Common Share Basic earnings per common share is calculated by dividing income allocated to common stockholders for basic earnings per common share by the weighted average number of common shares outstanding for the period, reduced by average unvested stock awards. Unvested stock awards with non-forfeitable rights to dividends, whether paid or unpaid, and stand-alone dividend participation rights are considered participating securities and are included in the computation of basic earnings per common share using the two class method whereby net income is allocated between common stock and participating securities. In periods of a net loss, no allocation is made to participating securities as they are not contractually required to fund net losses. Diluted earnings per common share is computed by dividing income allocated to common stockholders for basic earnings per common share, adjusted for earnings reallocated from participating securities, by the weighted average number of common shares outstanding for the period increased for the dilutive effect of unexercised stock options, warrants and unvested stock awards using the treasury stock method. Contingently issuable shares are included in the calculation of earnings per common share as if the end of the respective period was the end of the contingency period.
Reclassification, Policy [Policy Text Block]	Reclassifications Certain amounts presented for prior periods have been reclassified to conform to the current period presentation.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements Adopted in 2017 ASU No. 2016-06, Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments . The amendments in this ASU clarified the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. A company performing the assessment under these amendments is required to assess the embedded call (put) options solely in accordance with a four-step decision sequence, without also considering whether the contingency is related to interest rates or credit risks. The adoption of this standard had no impact on the Company's consolidated financial position, results of operations or cash flows. ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting . The amendments in this ASU simplified several aspects of the accounting for share-based payment transactions. The amendment requiring the recognition of excess tax benefits and deficiencies as income tax benefit or expense as opposed to additional paid-in-capital was applied prospectively and resulted in the recognition of $3.7 million in excess tax benefits in the consolidated statement of income line item " Provision for income taxes " for the year ended December 31, 2017 , increasing net income by the same amount and increasing basic and diluted earnings per share by $0.03 . The Company retrospectively adopted the amendments requiring the classification of excess tax benefits and deficiencies with other income tax cash flows as operating activities and cash paid when directly withholding shares as financing activities in the accompanying consolidated statements of cash flows; the impact of adoption was not material. The Company elected to continue its practice of estimating the number of awards expected to vest in determining the amount of compensation cost to be recognized related to share-based payment transactions. ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . This ASU removed step two of the goodwill impairment test. The Company elected to early adopt this ASU in the third quarter of 2017. Adoption had no impact on the Company's consolidated financial position, results of operations or cash flows. ASU No. 2017-08, Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. The amendments in this ASU required certain premiums on callable debt securities to be amortized to the earliest call date. The amortization period for callable debt securities purchased at a discount were not impacted. The Company early-adopted this ASU with no material impact on the Company's consolidated financial position, results of operations or cash flows. ASU No. 2017-12, Derivatives and Hedging (Topic 815) : Targeted Improvements to Accounting for Hedging Activities. This ASU eliminated the requirement to separately measure and report hedge ineffectiveness after initial qualification. For qualifying cash flow and net investment hedges, the entire change in the fair value of the hedging instrument included in the assessment of hedge effectiveness is recorded in OCI, and amounts deferred in AOCI are reclassified to earnings in the same income statement line item that is used to present the earnings effect of the hedged item when the hedged item affects earnings. The new guidance also permits a qualitative effectiveness assessment for certain hedges instead of a quantitative test, such as a regression analysis, if the company can reasonably support an expectation of high effectiveness throughout the term of the hedge. The ASU allows for more hedging strategies to be eligible for hedge accounting. From a disclosure standpoint, to help users of the financial statements better understand the effects of hedge accounting, the guidance requires revised tabular disclosures that focus on the effect of hedge accounting by income statement line, and eliminates the requirement to disclose hedge ineffectiveness because this amount is no longer separately measured. The adoption of this ASU had no impact on the Company's consolidated financial position, results of operations or cash flows .
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	Recent Accounting Pronouncements Not Yet Adopted In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which will supersede the revenue recognition requirements in Topic 605, Revenue Recognition , and most industry-specific revenue recognition guidance throughout the Accounting Standards Codification. The amendments in this update affect any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets unless those contracts, including leases and insurance contracts, are within the scope of other standards. The amendments establish a core principle requiring the recognition of revenue to depict the transfer of goods or services to customers in an amount reflecting the consideration to which the entity expects to be entitled in exchange for such goods or services. The amendments also require expanded disclosures concerning the nature, amount, timing and uncertainty of revenues and cash flows arising from contracts with customers. Financial instruments and lease contracts are generally outside the scope of the ASU as are revenues that are in the scope of ASC 860 "Transfers and Servicing", ASC 460 "Guarantees" and ASC 815 "Derivatives and Hedging". The FASB has issued subsequent ASUs to clarify certain aspects of ASU 2014-09, without changing the core principle of the guidance and to defer the effective date of ASU 2014-09 to annual periods and interim periods within fiscal years beginning after December 15, 2017. Substantially all of the Company's revenues have historically been generated from activities that are outside the scope of the ASU. Service charges on deposit accounts, which totaled approximately $13 million for the year ended December 31, 2017 is the most significant category of revenue identified as within the scope of the ASU; however, management does not expect the amount and timing of recognition of such revenue to be impacted by adoption. The Company will apply this ASU for the first quarter of 2018 to contracts not completed on the date of adoption using the modified retrospective method. The Company does not expect adoption to have a significant impact on its financial condition, results of operations or cash flows and therefore does not expect to record any cumulative effect of initial application. Adoption of the ASU will result in some expanded disclosure about revenue from contracts with customers. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The amendments in the ASU that are expected to be applicable to the Company include provisions to: 1) eliminate the available for sale classification for equity securities and require investments in equity securities (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income, provided that equity investments that do not have readily determinable fair values may be re-measured at fair value upon occurrence of an observable price change or recognition of impairment, 2) eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet, and 3) require public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. The amendments also clarify that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity's other deferred tax assets, which is consistent with the Company's current practice. This ASU will be adopted by the Company for the first quarter of 2018 by means of a cumulative-effect adjustment to the balance sheet, except for amendments related to equity securities without readily determinable fair values, which will be applied prospectively. Equity investments that will no longer be reported as available for sale and for which fair value changes will be recognized in earnings after adoption totaled $64 million and had unrealized gains of $3.6 million at December 31, 2017 . The Company expects to record a cumulative effect adjustment to reclassify unrealized gains on these equity securities, net of related income taxes, of $2.2 million from AOCI to retained earnings upon adoption. Adoption of the ASU will impact the Company's disclosures about the fair values of financial instruments. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The amendments in this ASU require a lessee to recognize in the statement of financial position a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for lease terms longer than one year. Accounting applied by lessors is largely unchanged by this ASU. The amendments in this ASU are effective for the Company for interim and annual periods in fiscal years beginning after December 15, 2018. Early adoption is permitted; however, the Company does not intend to early adopt this ASU. Lessees and lessors are required to apply the provisions of the ASU at the beginning of the earliest period presented using a modified retrospective approach. Management is in the process of evaluating the impact of adoption of this ASU on its consolidated financial statements, processes and controls. The Company has acquired and implemented software to facilitate calculation and reporting of the lease liability and right of use asset. Certain accounting policy decisions have been made including use of the incremental borrowing rate to determine the discount rate and assumptions around inclusion of renewals in lease terms. The most significant impact of adoption is expected to be the recognition, as lessee, of new right-of-use assets and lease liabilities on the consolidated balance sheet for real estate leases currently classified as operating leases. At its November 29, 2017 meeting, the FASB proposed allowing entities the option of applying the provisions of the ASU at the effective date without adjusting the comparative periods presented. The Company is monitoring these and other proposed modifications to the requirements of this ASU. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326); Measurement of Credit Losses on Financial Instruments. The ASU introduces new guidance which makes substantive changes to the accounting for credit losses. The ASU introduces the CECL model which applies to financial assets subject to credit losses and measured at amortized cost, as well as certain off-balance sheet credit exposures. This includes loans, loan commitments, standby letters of credit, net investments in leases recognized by a lessor and HTM debt securities. The CECL model requires an entity to estimate credit losses expected over the life of an exposure, considering information about historical events, current conditions and reasonable and supportable forecasts, and is generally expected to result in earlier recognition of credit losses. The ASU also modifies certain provisions of the current OTTI model for AFS debt securities. Credit losses on AFS debt securities will be limited to the difference between the security's amortized cost basis and its fair value, and be recognized through an allowance for credit losses rather than as a direct reduction in amortized cost basis. The ASU also provides for a simplified accounting model for purchased financial assets with more than insignificant credit deterioration since their origination. The ASU requires expanded disclosures including, but not limited to (i) information about the methods and assumptions used to estimate expected credit losses, including changes in the factors that influenced management's estimate and the reasons for those changes, (ii) for financing receivables and net investment in leases measured at amortized cost, further disaggregation of information about the credit quality of those assets and (iii) a rollforward of the allowance for credit losses for AFS and HTM securities. The amendments in this ASU are effective for the Company for interim and annual periods in fiscal years beginning after December 15, 2019. Early adoption is permitted, however, the Company does not intend to early adopt this ASU. Management is in the process of evaluating the impact of adoption of this ASU on its consolidated financial statements, processes and controls and is not currently able to reasonably estimate the impact of adoption on the Company's consolidated financial position, results of operations or cash flows; however, adoption is likely to lead to significant changes in accounting policies related to, and the methods employed in estimating, the ALLL. It is possible that the impact will be material to the Company's consolidated financial position and results of operations. To date, the Company has completed a gap analysis, adopted a detailed implementation plan, established a formal governance structure for the project, selected and implemented credit loss models for key portfolio segments, chosen loss estimation methodologies for key portfolio segments, and selected a software solution to serve as its CECL platform. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The amendments in this ASU provide guidance on eight specific cash flow classification issues where there has been diversity in practice. The guidance in the ASU that is expected to be most applicable to the Company requires: (1) cash payments for debt prepayment or extinguishment costs to be classified as cash outflows for financing activities, (2) proceeds from settlement of insurance claims to be classified on the basis of the nature of the loss and (3) cash proceeds from settlement of bank-owned life insurance policies to be classified as cash flows from investing activities. Cash payments for premiums on bank-owned life insurance may be classified as cash flows for investing activities, operating activities or a combination thereof. The amendments in this ASU will be adopted for the first quarter of 2018 and will be applied retrospectively to each period presented. The provisions of this ASU are generally consistent with the Company's current practice; therefore, adoption is not expected to significantly impact the Company's consolidated cash flows. In February 2018, the FASB issued ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . The amendments in this ASU allow a reclassification from AOCI to retained earnings of stranded tax effects in AOCI resulting from enactment of the Tax Cuts and Jobs Act (the “Act”). The amount of that reclassification is the difference between (1) the amount initially charged or credited directly to other comprehensive income at the previously enacted federal corporate income tax rate that remains in AOCI and (2) the amount that would have been charged or credited using the newly enacted federal corporate income tax rate, excluding the effect of any valuation allowance previously charged to income from continuing operations. The amendments in this ASU also require certain disclosures about stranded tax effects. The amendments in this ASU are effective for the Company for interim and annual periods beginning after December 15, 2018 with early adoption permitted. The Company intends to early adopt this ASU in the first quarter of 2018 with the amendments in this ASU being applied at the beginning of the period. Stranded tax effects resulting from the Act totaled approximately $11.7 million at December 31, 2017.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Common Share	The computation of basic and diluted earnings per common share is presented below for the years ended December 31, 2017 , 2016 and 2015 (in thousands, except share and per share data): c 2017 2016 2015 Basic earnings per common share: Numerator: Net income $ 614,273 $ 225,741 $ 251,660 Distributed and undistributed earnings allocated to participating securities (23,250 ) (8,760 ) (9,742 ) Income allocated to common stockholders for basic earnings per common share $ 591,023 $ 216,981 $ 241,918 Denominator: Weighted average common shares outstanding 106,574,448 104,097,182 103,187,530 Less average unvested stock awards (1,104,035 ) (1,157,378 ) (1,128,416 ) Weighted average shares for basic earnings per common share 105,470,413 102,939,804 102,059,114 Basic earnings per common share $ 5.60 $ 2.11 $ 2.37 Diluted earnings per common share: Numerator: Income allocated to common stockholders for basic earnings per common share $ 591,023 $ 216,981 $ 241,918 Adjustment for earnings reallocated from participating securities (263 ) 62 54 Income used in calculating diluted earnings per common share $ 590,760 $ 217,043 $ 241,972 Denominator: Weighted average shares for basic earnings per common share 105,470,413 102,939,804 102,059,114 Dilutive effect of stock options 387,074 716,366 913,036 Weighted average shares for diluted earnings per common share 105,857,487 103,656,170 102,972,150 Diluted earnings per common share $ 5.58 $ 2.09 $ 2.35
Potentially Dilutive Securities Outstanding Categorized	The following potentially dilutive securities were outstanding at December 31, 2017 , 2016 , and 2015 but excluded from the calculation of diluted earnings per common share for the periods indicated because their inclusion would have been anti-dilutive: 2017 2016 2015 Unvested shares and share units 1,431,761 1,303,208 1,040,385 Stock options and warrants 1,850,279 1,850,279 1,851,376

Acquisition Activity Business C

Acquisition Activity Business Combination (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair values of assets acquired and liabilities assumed (in thousands): Assets: Loans held for investment $ 173,809 Loans held for sale 82,143 Servicing rights 10,418 Other assets 4,397 Total assets 270,767 Total liabilities 3,620 Estimated fair value of net assets acquired 267,147 Consideration issued 277,553 Excess of consideration issued over fair value of net assets acquired $ 10,406

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	Investment securities available for sale consisted of the following at December 31, 2017 and 2016 (in thousands): 2017 Amortized Cost Gross Unrealized Fair Value Gains Losses U.S. Treasury securities $ 24,981 $ — $ (28 ) $ 24,953 U.S. Government agency and sponsored enterprise residential MBS 2,043,373 16,094 (1,440 ) 2,058,027 U.S. Government agency and sponsored enterprise commercial MBS 233,522 1,330 (344 ) 234,508 Private label residential MBS and CMOs 613,732 16,473 (1,958 ) 628,247 Private label commercial MBS 1,033,022 13,651 (258 ) 1,046,415 Single family rental real estate-backed securities 559,741 3,823 (858 ) 562,706 Collateralized loan obligations 720,429 3,252 — 723,681 Non-mortgage asset-backed securities 119,939 1,808 — 121,747 Preferred stocks 59,912 3,631 — 63,543 State and municipal obligations 640,511 17,606 (914 ) 657,203 SBA securities 534,534 16,208 (60 ) 550,682 Other debt securities 4,090 5,030 — 9,120 $ 6,587,786 $ 98,906 $ (5,860 ) $ 6,680,832 2016 Amortized Cost Gross Unrealized Fair Value Gains Losses U.S. Treasury securities $ 4,999 $ 6 $ — $ 5,005 U.S. Government agency and sponsored enterprise residential MBS 1,513,028 15,922 (1,708 ) 1,527,242 U.S. Government agency and sponsored enterprise commercial MBS 126,754 670 (2,838 ) 124,586 Private label residential MBS and CMOs 334,167 42,939 (2,008 ) 375,098 Private label commercial MBS 1,180,386 9,623 (2,385 ) 1,187,624 Single family rental real estate-backed securities 858,339 4,748 (1,836 ) 861,251 Collateralized loan obligations 487,678 868 (1,250 ) 487,296 Non-mortgage asset-backed securities 187,660 2,002 (2,926 ) 186,736 Preferred stocks 76,180 12,027 (4 ) 88,203 State and municipal obligations 705,884 3,711 (11,049 ) 698,546 SBA securities 517,129 7,198 (421 ) 523,906 Other debt securities 3,999 4,092 — 8,091 $ 5,996,203 $ 103,806 $ (26,425 ) $ 6,073,584
Investments Classified by Contractual Maturity Date	At December 31, 2017 , contractual maturities of investment securities available for sale, adjusted for anticipated prepayments of mortgage-backed and other pass-through securities, were as follows (in thousands): Amortized Cost Fair Value Due in one year or less $ 663,592 $ 674,291 Due after one year through five years 3,196,717 3,232,157 Due after five years through ten years 2,229,852 2,264,131 Due after ten years 437,713 446,710 Preferred stocks with no stated maturity 59,912 63,543 $ 6,587,786 $ 6,680,832
Schedule of Realized Gain (Loss)	The following table provides information about gains and losses on investment securities available for sale for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 2016 2015 Proceeds from sale of investment securities available for sale $ 1,287,591 $ 1,127,983 $ 1,114,020 Gross realized gains $ 37,530 $ 14,924 $ 8,955 Gross realized losses (4,064 ) — (475 ) Net realized gain 33,466 14,924 8,480 OTTI — (463 ) — Gain on investment securities available for sale, net $ 33,466 $ 14,461 $ 8,480
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	The following tables present the aggregate fair value and the aggregate amount by which amortized cost exceeded fair value for investment securities in unrealized loss positions, aggregated by investment category and length of time that individual securities had been in continuous unrealized loss positions at December 31, 2017 and 2016 (in thousands): 2017 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Treasury securities $ 24,953 $ (28 ) $ — $ — $ 24,953 $ (28 ) U.S. Government agency and sponsored enterprise residential MBS 471,120 (1,141 ) 13,028 (299 ) 484,148 (1,440 ) U.S. Government agency and sponsored enterprise commercial MBS 26,265 (344 ) — — 26,265 (344 ) Private label residential MBS and CMOs 330,068 (1,858 ) 5,083 (100 ) 335,151 (1,958 ) Private label commercial MBS 81,322 (258 ) — — 81,322 (258 ) Single family rental real estate-backed securities 94,750 (858 ) — — 94,750 (858 ) State and municipal obligations 30,715 (49 ) 60,982 (865 ) 91,697 (914 ) SBA securities 21,300 (10 ) 15,427 (50 ) 36,727 (60 ) $ 1,080,493 $ (4,546 ) $ 94,520 $ (1,314 ) $ 1,175,013 $ (5,860 ) 2016 Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Government agency and sponsored enterprise residential MBS $ 191,463 $ (628 ) $ 112,391 $ (1,080 ) $ 303,854 $ (1,708 ) U.S. Government agency and sponsored enterprise commercial MBS 89,437 (2,838 ) — — 89,437 (2,838 ) Private label residential MBS and CMOs 122,142 (1,680 ) 8,074 (328 ) 130,216 (2,008 ) Private label commercial MBS 169,535 (2,370 ) 24,985 (15 ) 194,520 (2,385 ) Single family rental real estate-backed securities 139,867 (842 ) 176,057 (994 ) 315,924 (1,836 ) Collateralized loan obligations 69,598 (402 ) 173,983 (848 ) 243,581 (1,250 ) Non-mortgage asset-backed securities 139,477 (2,926 ) — — 139,477 (2,926 ) Preferred stocks 10,087 (4 ) — — 10,087 (4 ) State and municipal obligations 448,180 (11,049 ) — — 448,180 (11,049 ) SBA securities 4,204 (13 ) 20,076 (408 ) 24,280 (421 ) $ 1,383,990 $ (22,752 ) $ 515,566 $ (3,673 ) $ 1,899,556 $ (26,425 )

Loans and Allowance for Loan 31

Loans and Allowance for Loan and Lease Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of Loans Categorized	At December 31, 2017 and 2016 , loans consisted of the following (dollars in thousands): 2017 Covered Loans Percent of Total Non-Covered Loans ACI Non-ACI Total Residential and other consumer: 1-4 single family residential $ 4,116,814 $ 479,068 $ 26,837 $ 4,622,719 21.6 % Home equity loans and lines of credit 1,654 — 361 2,015 — % Other consumer loans 20,512 — — 20,512 0.1 % 4,138,980 479,068 27,198 4,645,246 21.7 % Commercial: Multi-family 3,215,697 — — 3,215,697 15.0 % Non-owner occupied commercial real estate 4,485,276 — — 4,485,276 21.0 % Construction and land 310,999 — — 310,999 1.5 % Owner occupied commercial real estate 2,014,908 — — 2,014,908 9.4 % Commercial and industrial 4,145,785 — — 4,145,785 19.4 % Commercial lending subsidiaries 2,553,576 — — 2,553,576 12.0 % 16,726,241 — — 16,726,241 78.3 % Total loans 20,865,221 479,068 27,198 21,371,487 100.0 % Premiums, discounts and deferred fees and costs, net 48,165 — (3,148 ) 45,017 Loans including premiums, discounts and deferred fees and costs 20,913,386 479,068 24,050 21,416,504 Allowance for loan and lease losses (144,537 ) — (258 ) (144,795 ) Loans, net $ 20,768,849 $ 479,068 $ 23,792 $ 21,271,709 2016 Covered Loans Percent of Total Non-Covered Loans ACI Non-ACI Total Residential and other consumer: 1-4 single family residential $ 3,422,425 $ 532,348 $ 36,675 $ 3,991,448 20.6 % Home equity loans and lines of credit 1,120 3,894 47,629 52,643 0.3 % Other consumer loans 24,365 — — 24,365 0.1 % 3,447,910 536,242 84,304 4,068,456 21.0 % Commercial: Multi-family 3,824,973 — — 3,824,973 19.8 % Non-owner occupied commercial real estate 3,739,235 — — 3,739,235 19.3 % Construction and land 311,436 — — 311,436 1.6 % Owner occupied commercial real estate 1,736,858 — — 1,736,858 9.0 % Commercial and industrial 3,391,614 — — 3,391,614 17.5 % Commercial lending subsidiaries 2,280,685 — — 2,280,685 11.8 % 15,284,801 — — 15,284,801 79.0 % Total loans 18,732,711 536,242 84,304 19,353,257 100.0 % Premiums, discounts and deferred fees and costs, net 48,641 — (6,504 ) 42,137 Loans including premiums, discounts and deferred fees and costs 18,781,352 536,242 77,800 19,395,394 Allowance for loan and lease losses (150,853 ) — (2,100 ) (152,953 ) Loans, net $ 18,630,499 $ 536,242 $ 75,700 $ 19,242,441 Included in non-covered loans above are $34 million and $47 million at December 31, 2017 and 2016 , respectively, of ACI commercial loans acquired in the FSB Acquisition.
Direct Financing Lease, Lease Income [Table Text Block]	The following table presents the components of the investment in direct financing leases as of December 31, 2017 and 2016 (in thousands): 2017 2016 Total minimum lease payments to be received $ 792,064 $ 689,631 Estimated unguaranteed residual value of leased assets 17,872 3,704 Gross investment in direct financing leases 809,936 693,335 Unearned income (76,900 ) (55,891 ) Initial direct costs 5,184 5,287 $ 738,220 $ 642,731
Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block]	As of December 31, 2017 , future minimum lease payments to be received under direct financing leases were as follows (in thousands): Years Ending December 31: 2018 $ 189,017 2019 158,846 2020 121,930 2021 74,536 2022 49,781 Thereafter 197,954 $ 792,064
Accretable Yield Rollfoward [Table Text Block]	Changes in the accretable yield on ACI loans for the years ended December 31, 2017 , 2016 , and 2015 were as follows (in thousands): Balance at December 31, 2014 $ 1,005,312 Reclassifications from non-accretable difference 192,291 Accretion (295,038 ) Balance at December 31, 2015 902,565 Reclassifications from non-accretable difference 76,751 Accretion (303,931 ) Balance at December 31, 2016 675,385 Reclassifications from non-accretable difference 81,501 Accretion (301,827 ) Balance at December 31, 2017 $ 455,059 Reclassifications from non-accretable difference in the table above for the year ended December 31, 2017 included $16.3 million of remaining accretable yield included in the determination of the recorded investment in the pool of ACI home equity loans and lines of credit, which was sold in its entirety in the fourth quarter of 2017.
Covered Loan Sales - Residential [Table Text Block]	During the years ended December 31, 2017 , 2016 and 2015 , the Company sold covered residential loans to third parties on a non-recourse basis. The following table summarizes the impact of these transactions (in thousands): 2017 2016 2015 UPB of loans sold $ 203,970 $ 241,348 $ 249,038 Cash proceeds, net of transaction costs $ 169,828 $ 171,367 $ 207,425 Recorded investment in loans sold 152,422 185,837 172,496 Gain (loss) on sale of covered loans, net $ 17,406 $ (14,470 ) $ 34,929 Gain (loss) on FDIC indemnification, net $ (1,523 ) $ 11,615 $ (28,051 )
Allowance for Credit Losses on Financing Receivables	Activity in the ALLL for the years ended December 31, 2017 , 2016 , and 2015 is summarized as follows (in thousands): 2017 Residential and Other Consumer Commercial Total Beginning balance $ 11,503 $ 141,450 $ 152,953 Provision for (recovery of) loan losses: Covered loans 1,418 (60 ) 1,358 Non-covered loans 1,034 66,355 67,389 Total provision 2,452 66,295 68,747 Charge-offs: Covered loans (3,327 ) — (3,327 ) Non-covered loans (1 ) (77,865 ) (77,866 ) Total charge-offs (3,328 ) (77,865 ) (81,193 ) Recoveries: Covered loans 67 60 127 Non-covered loans 26 4,135 4,161 Total recoveries 93 4,195 4,288 Ending balance $ 10,720 $ 134,075 $ 144,795 2016 Residential and Other Consumer Commercial Total Beginning balance $ 16,211 $ 109,617 $ 125,828 Provision for (recovery of) loan losses: Covered loans (1,632 ) (49 ) (1,681 ) Non-covered loans (1,814 ) 54,406 52,592 Total provision (3,446 ) 54,357 50,911 Charge-offs: Covered loans (1,216 ) — (1,216 ) Non-covered loans (152 ) (25,742 ) (25,894 ) Total charge-offs (1,368 ) (25,742 ) (27,110 ) Recoveries: Covered loans 80 49 129 Non-covered loans 26 3,169 3,195 Total recoveries 106 3,218 3,324 Ending balance $ 11,503 $ 141,450 $ 152,953 2015 Residential and Other Consumer Commercial Total Beginning balance $ 11,515 $ 84,027 $ 95,542 Provision for (recovery of) loan losses: Covered loans 2,317 (66 ) 2,251 Non-covered loans 3,988 38,072 42,060 Total provision 6,305 38,006 44,311 Charge-offs: Covered loans (1,680 ) — (1,680 ) Non-covered loans — (13,719 ) (13,719 ) Total charge-offs (1,680 ) (13,719 ) (15,399 ) Recoveries: Covered loans 39 66 105 Non-covered loans 32 1,237 1,269 Total recoveries 71 1,303 1,374 Ending balance $ 16,211 $ 109,617 $ 125,828 The following table presents information about the balance of the ALLL and related loans as of December 31, 2017 and 2016 (in thousands): 2017 2016 Residential and Other Consumer Commercial Total Residential and Other Consumer Commercial Total Allowance for loan and lease losses: Ending balance $ 10,720 $ 134,075 $ 144,795 $ 11,503 $ 141,450 $ 152,953 Covered loans: Ending balance $ 258 $ — $ 258 $ 2,100 $ — $ 2,100 Ending balance: non-ACI loans individually evaluated for impairment $ 118 $ — $ 118 $ 529 $ — $ 529 Ending balance: non-ACI loans collectively evaluated for impairment $ 140 $ — $ 140 $ 1,571 $ — $ 1,571 Ending balance: ACI loans $ — $ — $ — $ — $ — $ — Non-covered loans: Ending balance $ 10,462 $ 134,075 $ 144,537 $ 9,403 $ 141,450 $ 150,853 Ending balance: loans individually evaluated for impairment $ 63 $ 18,776 $ 18,839 $ 12 $ 19,229 $ 19,241 Ending balance: loans collectively evaluated for impairment $ 10,399 $ 115,299 $ 125,698 $ 9,391 $ 122,221 $ 131,612 Ending balance: ACI loans $ — $ — $ — $ — $ — $ — Loans: 0 Covered loans: Ending balance $ 503,118 $ — $ 503,118 $ 614,042 $ — $ 614,042 Ending balance: non-ACI loans individually evaluated for impairment $ 2,221 $ — $ 2,221 $ 12,396 $ — $ 12,396 Ending balance: non-ACI loans collectively evaluated for impairment $ 21,829 $ — $ 21,829 $ 65,404 $ — $ 65,404 Ending balance: ACI loans $ 479,068 $ — $ 479,068 $ 536,242 $ — $ 536,242 Non-covered loans: Ending balance $ 4,196,080 $ 16,717,306 $ 20,913,386 $ 3,495,775 $ 15,285,577 $ 18,781,352 Ending balance: loans, other than ACI loans, individually evaluated for impairment $ 1,234 $ 173,706 $ 174,940 $ 561 $ 176,932 $ 177,493 Ending balance: loans, other than ACI loans, collectively evaluated for impairment $ 4,194,846 $ 16,509,824 $ 20,704,670 $ 3,495,207 $ 15,061,707 $ 18,556,914 Ending balance: ACI loans $ — $ 33,776 $ 33,776 $ 7 $ 46,938 $ 46,945
Impaired Financing Receivables	The table below presents information about loans or ACI pools identified as impaired as of December 31, 2017 and 2016 (in thousands): 2017 2016 Recorded Investment UPB Related Specific Allowance Recorded Investment UPB Related Specific Allowance Non-covered loans: With no specific allowance recorded: 1-4 single family residential $ 120 $ 122 $ — $ — $ — $ — Non-owner occupied commercial real estate 10,922 10,838 — 510 512 — Construction and land 1,175 1,175 — 1,238 1,238 — Owner occupied commercial real estate 22,002 22,025 — 16,834 16,894 — Commercial and industrial Taxi medallion loans 13,560 13,559 — 18,107 18,107 — Other commercial and industrial 345 374 — 6,172 6,172 — Commercial lending subsidiaries — — — 10,620 10,510 — With a specific allowance recorded: 1-4 single family residential 1,114 1,090 63 561 546 12 Multi-family 23,173 23,175 1,732 — — — Owner occupied commercial real estate 3,075 3,079 2,960 491 513 263 Commercial and industrial Taxi medallion loans 92,507 92,508 12,214 73,131 73,147 5,948 Other commercial and industrial 3,626 3,624 1,540 29,452 29,463 9,168 Commercial lending subsidiaries 3,321 3,296 330 21,712 21,605 3,850 Total: Residential and other consumer $ 1,234 $ 1,212 $ 63 $ 561 $ 546 $ 12 Commercial 173,706 173,653 18,776 178,267 178,161 19,229 $ 174,940 $ 174,865 $ 18,839 $ 178,828 $ 178,707 $ 19,241 Covered loans: Non-ACI loans: With no specific allowance recorded: 1-4 single family residential $ 1,061 $ 1,203 $ — $ 1,169 $ 1,391 $ — Home equity loans and lines of credit — — — 2,255 2,286 — With a specific allowance recorded: 1-4 single family residential 1,160 1,314 118 1,272 1,514 181 Home equity loans and lines of credit — — — 7,700 7,804 348 $ 2,221 $ 2,517 $ 118 $ 12,396 $ 12,995 $ 529 Non-covered impaired loans include commercial real estate ACI loans modified in TDRs with a carrying value of $1.3 million as of December 31, 2016 . Interest income recognized on impaired loans and pools for the year ended December 31, 2017 was approximately $9.6 million . The interest income recognized on impaired loans for the years ended December 31, 2016 and 2015 was not material. The following table presents the average recorded investment in impaired loans for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 2016 2015 Non-Covered Loans Covered Non-ACI Loans Non-Covered Loans Covered Non-ACI Non-Covered Loans Covered Non-ACI Residential and other consumer: 1-4 single family residential $ 868 $ 2,345 $ 301 $ 3,067 $ 82 $ 3,655 Home equity loans and lines of credit — 8,403 — 9,225 4,830 868 $ 10,748 301 $ 12,292 82 $ 8,485 Commercial: Multi-family 4,259 — 291 Non-owner occupied commercial real estate 5,537 710 1,001 Construction and land 2,789 797 — Owner occupied commercial real estate 19,882 14,645 5,117 Commercial and industrial Taxi medallion loans 108,977 45,012 — Other commercial and industrial 38,275 40,443 35,976 Commercial lending subsidiaries 22,865 15,052 14,835 202,584 116,659 57,220 $ 203,452 $ 116,960 $ 57,302 In addition to the above, a pool of ACI home equity loans and lines of credit was impaired during 2017. All of the loans from this pool were sold in the fourth quarter of 2017. The average balance of impaired ACI home equity loans and lines of credit for the year ended December 31, 2017 was $3.9 million .
Schedule of Recorded Investment in Loans, Other than ACI Loans, on Non-Accrual Status	The following table presents the recorded investment in loans on non-accrual status as of December 31, 2017 and 2016 (in thousands): 2017 2016 Non-Covered Loans Covered Non-Covered Loans Covered Non-ACI Loans Residential and other consumer: 1-4 single family residential $ 9,705 $ 1,010 $ 566 $ 918 Home equity loans and lines of credit — 331 — 2,283 Other consumer loans 821 — 2 — 10,526 $ 1,341 568 $ 3,201 Commercial: Non-owner occupied commercial real estate 12,716 559 Construction and land 1,175 1,238 Owner occupied commercial real estate 29,020 19,439 Commercial and industrial Taxi medallion loans 106,067 60,660 Other commercial and industrial 7,049 16,036 Commercial lending subsidiaries 3,512 32,645 159,539 130,577 $ 170,065 $ 131,145
Financing Receivable Credit Quality Indicators	The following tables summarize key indicators of credit quality for the Company's loans as of December 31, 2017 and 2016 . Amounts include premiums, discounts and deferred fees and costs (in thousands): 1-4 Single Family Residential credit exposure for non-covered loans, based on original LTV and FICO score: 2017 FICO LTV 720 or less 721 - 740 741 - 760 761 or greater Total 60% or less $ 92,316 $ 117,319 $ 185,193 $ 815,828 $ 1,210,656 60% - 70% 101,158 103,506 147,592 590,693 942,949 70% - 80% 149,958 183,376 324,887 1,139,969 1,798,190 More than 80% 33,776 32,563 30,404 125,415 222,158 $ 377,208 $ 436,764 $ 688,076 $ 2,671,905 $ 4,173,953 2016 FICO LTV 720 or less 721 - 740 741 - 760 761 or greater Total 60% or less $ 87,035 $ 113,401 $ 163,668 $ 751,291 $ 1,115,395 60% - 70% 80,694 94,592 124,180 523,970 823,436 70% - 80% 110,509 148,211 276,425 907,450 1,442,595 More than 80% 22,115 9,058 15,470 42,280 88,923 $ 300,353 $ 365,262 $ 579,743 $ 2,224,991 $ 3,470,349 Commercial credit exposure, based on internal risk rating: 2017 Commercial and Industrial Multi-Family Non-Owner Occupied Commercial Real Estate Construction Owner Occupied Commercial Real Estate Taxi Medallion Loans Other Commercial and Industrial Commercial Lending Subsidiaries Total Pass $ 3,124,819 $ 4,360,827 $ 305,043 $ 1,954,464 $ — $ 3,965,241 $ 2,478,998 $ 16,189,392 Special mention 34,837 33,094 — 22,161 — 37,591 55,551 183,234 Substandard 59,297 80,880 5,441 33,145 104,682 27,010 27,950 338,405 Doubtful — — — 2,972 1,385 1,918 — 6,275 $ 3,218,953 $ 4,474,801 $ 310,484 $ 2,012,742 $ 106,067 $ 4,031,760 $ 2,562,499 $ 16,717,306 2016 Commercial and Industrial Multi-Family Non-Owner Occupied Commercial Real Estate Construction and Land Owner Occupied Commercial Real Estate Taxi Medallion Loans Other Commercial and Industrial Commercial Lending Subsidiaries Total Pass $ 3,811,822 $ 3,694,931 $ 309,675 $ 1,672,199 $ 40,460 $ 3,112,590 $ 2,255,444 $ 14,897,121 Special mention 12,000 7,942 — 33,274 — 19,009 — 72,225 Substandard 5,852 28,935 1,238 30,377 138,035 68,704 31,572 304,713 Doubtful — — — — 178 8,162 3,178 11,518 $ 3,829,674 $ 3,731,808 $ 310,913 $ 1,735,850 $ 178,673 $ 3,208,465 $ 2,290,194 $ 15,285,577
Schedule of Past Due Financing Receivables	The following table presents an aging of loans as of December 31, 2017 and 2016 . Amounts include premiums, discounts and deferred fees and costs (in thousands): 2017 2016 Current 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Current 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Non-covered loans: 1-4 single family residential $ 4,145,079 $ 17,224 $ 6,094 $ 5,556 $ 4,173,953 $ 3,457,606 $ 10,355 $ 325 $ 2,063 $ 3,470,349 Home equity loans and lines of credit 1,633 21 — — 1,654 1,120 — — — 1,120 Other consumer loans 19,958 15 — 500 20,473 24,306 — — — 24,306 Multi-family 3,218,953 — — — 3,218,953 3,829,674 — — — 3,829,674 Non-owner occupied commercial real estate 4,464,967 7,549 — 2,285 4,474,801 3,730,470 754 — 584 3,731,808 Construction and land 309,309 — — 1,175 310,484 309,675 — — 1,238 310,913 Owner occupied commercial real estate 2,004,397 1,292 499 6,554 2,012,742 1,726,826 1,557 797 6,670 1,735,850 Commercial and industrial Taxi medallion loans 88,394 6,048 3,333 8,292 106,067 137,856 7,037 4,563 29,217 178,673 Other commercial and industrial 4,025,784 4,291 291 1,394 4,031,760 3,198,008 2,515 954 6,988 3,208,465 Commercial lending subsidiaries 2,561,647 852 — — 2,562,499 2,284,435 12 3,247 2,500 2,290,194 $ 20,840,121 $ 37,292 $ 10,217 $ 25,756 $ 20,913,386 $ 18,699,976 $ 22,230 $ 9,886 $ 49,260 $ 18,781,352 Covered loans: Non-ACI loans: 1-4 single family residential $ 21,076 $ 1,603 $ — $ 1,010 $ 23,689 $ 29,406 $ 481 $ — $ 918 $ 30,805 Home equity loans and lines of credit 30 — — 331 361 43,129 1,255 534 2,077 46,995 $ 21,106 $ 1,603 $ — $ 1,341 $ 24,050 $ 72,535 $ 1,736 $ 534 $ 2,995 $ 77,800 ACI loans: 1-4 single family residential $ 448,125 $ 10,388 $ 2,719 $ 17,836 $ 479,068 $ 500,272 $ 13,524 $ 2,990 $ 15,562 $ 532,348 Home equity loans and lines of credit — — — — — 3,460 148 23 263 3,894 $ 448,125 $ 10,388 $ 2,719 $ 17,836 $ 479,068 $ 503,732 $ 13,672 $ 3,013 $ 15,825 $ 536,242
Concentration Risk Disclosure [Text Block]	At December 31, 2017 and 2016 , 1-4 single family residential loans outstanding were collateralized by property located in the following states (dollars in thousands): 2017 Percent of Total Non-Covered Loans Covered Loans Total Non-Covered Loans Total Loans California $ 1,094,058 $ 23,780 $ 1,117,838 26.2 % 23.9 % New York 873,360 16,847 890,207 20.9 % 19.0 % Florida 552,556 281,396 833,952 13.2 % 17.8 % Virginia 181,912 22,290 204,202 4.4 % 4.4 % Others 1,472,067 158,444 1,630,511 35.3 % 34.9 % $ 4,173,953 $ 502,757 $ 4,676,710 100.0 % 100.0 % 2016 Percent of Total Non-Covered Loans Covered Loans Total Non-Covered Loans Total Loans California $ 904,107 $ 37,330 $ 941,437 26.1 % 23.3 % Florida 487,294 300,198 787,492 14.0 % 19.5 % New York 763,824 16,403 780,227 22.0 % 19.3 % Virginia 152,113 30,818 182,931 4.4 % 4.5 % Others 1,163,011 178,404 1,341,415 33.5 % 33.4 % $ 3,470,349 $ 563,153 $ 4,033,502 100.0 % 100.0 % No other state represented borrowers with more than 4.0% of 1-4 single family residential loans outstanding at December 31, 2017 or 2016 .
Troubled Debt Restructurings on Financing Receivables [Table Text Block]	The following tables summarize loans that were modified in TDRs during the years ended December 31, 2017 , 2016 and 2015 , as well as loans modified during the years ended December 31, 2017 , 2016 and 2015 that experienced payment defaults during the periods (dollars in thousands): 2017 Loans Modified in TDRs TDRs Experiencing Payment Number of Recorded Number of Recorded Non-covered loans: 1-4 single family residential 7 $ 676 5 $ 595 Multi-family 2 23,173 — — Owner occupied commercial real estate 3 4,685 — — Commercial and industrial Taxi medallion loans 110 48,526 8 2,725 Other commercial and industrial 2 1,378 — — 124 $ 78,438 13 $ 3,320 2016 Loans Modified in TDRs TDRs Experiencing Payment Number of Recorded Number of Recorded Non-covered loans: 1-4 single family residential 2 $ 326 — $ — Owner occupied commercial real estate 3 5,117 1 491 Commercial and industrial Taxi medallion loans 74 64,854 15 8,657 Other commercial and industrial 8 23,247 2 1,482 Commercial lending subsidiaries 6 6,735 1 2,500 93 $ 100,279 19 $ 13,130 Covered loans: Non-ACI loans: Home equity loans and lines of credit 17 $ 2,016 1 $ 370 ACI loans: Owner occupied commercial real estate 1 $ 825 — $ — 2015 Loans Modified in TDRs TDRs Experiencing Payment Number of Recorded Number of Recorded Non-covered loans: Non-owner occupied commercial real estate 1 $ 548 — $ — Commercial and industrial Taxi medallion loans 2 1,260 1 627 3 $ 1,808 1 $ 627 Covered loans: Non-ACI loans: 1-4 single family residential 2 $ 239 — $ — Home equity loans and lines of credit 28 6,208 7 1,231 30 $ 6,447 7 $ 1,231 ACI loans: Owner occupied commercial real estate 1 $ 500 — $ —

FDIC Indemnification Asset (Tab

FDIC Indemnification Asset (Tables)	12 Months Ended
	Dec. 31, 2017
FDIC Indemnification Asset [Abstract]
Summary of the Gains and Losses Associated with Covered Assets	The following tables summarize the components of the gains and losses associated with covered assets, along with the related additions to or reductions in the amounts recoverable from the FDIC under the Loss Sharing Agreements, as reflected in the consolidated statements of income for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Transaction Net Loss on FDIC Net Impact Provision for losses on covered loans $ (1,358 ) $ 1,039 $ (319 ) Income from resolution of covered assets, net 27,450 (21,912 ) 5,538 Gain on sale of covered loans 17,406 (1,514 ) 15,892 Loss on covered OREO (203 ) 167 (36 ) $ 43,295 $ (22,220 ) $ 21,075 The following tables summarize the components of the gains and losses associated with covered assets, along with the related additions to or reductions in the amounts recoverable from the FDIC under the Loss Sharing Agreements, as reflected in the consolidated statements of income for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Transaction Net Loss on FDIC Net Impact Provision for losses on covered loans $ (1,358 ) $ 1,039 $ (319 ) Income from resolution of covered assets, net 27,450 (21,912 ) 5,538 Gain on sale of covered loans 17,406 (1,514 ) 15,892 Loss on covered OREO (203 ) 167 (36 ) $ 43,295 $ (22,220 ) $ 21,075 2016 Transaction Net Loss on FDIC Net Impact Recovery of losses on covered loans $ 1,681 $ (1,472 ) $ 209 Income from resolution of covered assets, net 36,155 (28,946 ) 7,209 Loss on sale of covered loans (14,470 ) 11,615 (2,855 ) Loss on covered OREO (1,301 ) 1,044 (257 ) $ 22,065 $ (17,759 ) $ 4,306 2015 Transaction Net Loss on FDIC Net Impact Provision for losses on covered loans $ (2,251 ) $ 1,826 $ (425 ) Income from resolution of covered assets, net 50,658 (40,395 ) 10,263 Gain on sale of covered loans 34,929 (28,051 ) 6,878 Loss on covered OREO (1,014 ) 678 (336 ) $ 82,322 $ (65,942 ) $ 16,380
Changes in the FDIC Indemnification Asset	Changes in the FDIC indemnification asset, and in the liability to the FDIC for recoveries related to assets previously covered under the Commercial Shared-Loss Agreement, for the years ended December 31, 2017 , 2016 and 2015 , were as follows (in thousands): Balance at December 31, 2014 $ 974,335 Amortization (109,411 ) Reduction for claims filed (59,139 ) Net loss on FDIC indemnification (65,942 ) Balance at December 31, 2015 739,843 Amortization (160,091 ) Reduction for claims filed (46,083 ) Net loss on FDIC indemnification (17,759 ) Balance at December 31, 2016 515,910 Amortization (176,466 ) Reduction for claims filed (21,589 ) Net loss on FDIC indemnification (22,220 ) Balance at December 31, 2017 $ 295,635
FDIC Asset and Liability	The balances at December 31, 2017 and 2016 are reflected in the consolidated balance sheets as follows (in thousands): 2017 2016 FDIC indemnification asset $ 295,635 $ 515,933 Other liabilities — (23 ) $ 295,635 $ 515,910

Equipment Under Operating Lea33

Equipment Under Operating Lease (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Schedule of Property Subject to or Available for Operating Lease [Table Text Block]	Equipment under operating lease consists primarily of railcars and other transportation equipment. The components of equipment under operating lease as of December 31, 2017 and 2016 are summarized as follows (in thousands): 2017 2016 Equipment under operating lease $ 674,434 $ 589,716 Less: accumulated depreciation (74,932 ) (49,802 ) Equipment under operating lease, net $ 599,502 $ 539,914 The Company recognized impairment of $4.1 million during the year ended December 31, 2016 , related to a group of tank cars impacted by new safety regulations. This impairment charge is included in " Depreciation of equipment under operating lease " in the accompanying consolidated statements of income. No impairment was recognized during the years ended December 31, 2017 and 2015.
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	At December 31, 2017 , scheduled minimum rental payments under operating leases were as follows (in thousands) Years Ending December 31: 2018 $ 50,173 2019 46,547 2020 40,956 2021 31,425 2022 25,185 Thereafter through 2032 58,304 $ 252,590

Premises and Equipment and Le34

Premises and Equipment and Lease Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment, Type [Abstract]
Property, Plant and Equipment [Table Text Block]	Premises and equipment are included in other assets in the accompanying consolidated balance sheets and are summarized as follows as of December 31, 2017 and 2016 (in thousands): 2017 2016 Buildings and improvements $ 18,793 $ 22,470 Leasehold improvements 70,298 68,403 Furniture, fixtures and equipment 35,675 36,094 Computer equipment 21,078 18,559 Software and software licensing rights 42,908 38,002 Aircraft and automobiles 11,744 11,857 200,496 195,385 Less: accumulated depreciation (121,477 ) (104,268 ) Premises and equipment, net $ 79,019 $ 91,117
Premises and Equipment and Lease Commitments	As of December 31, 2017 , future minimum rentals under non-cancelable operating leases with initial or remaining terms in excess of one year were as follows (in thousands): Years ending December 31: 2018 $ 22,340 2019 21,129 2020 17,541 2021 15,770 2022 11,712 Thereafter through 2034 48,183 $ 136,675

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposit Liabilities Disclosures [Text Block]	Deposits The following table presents average balances and weighted average rates paid on deposits for the years ended December 31, 2017 , 2016 and 2015 (dollars in thousands): 2017 2016 2015 Average Balance Average Rate Paid Average Balance Average Average Balance Average Demand deposits: Non-interest bearing $ 3,069,565 — % $ 2,968,192 — % $ 2,732,654 — % Interest bearing 1,586,390 0.81 % 1,382,717 0.60 % 1,169,921 0.49 % Money market 9,364,498 0.85 % 7,946,447 0.64 % 6,313,340 0.57 % Savings 365,603 0.21 % 415,205 0.23 % 536,026 0.32 % Time 6,094,336 1.27 % 5,326,630 1.12 % 4,305,857 1.11 % $ 20,480,392 0.83 % $ 18,039,191 0.66 % $ 15,057,798 0.61 % Time deposit accounts with balances of $100,000 or more totaled approximately $4.1 billion and $3.9 billion at December 31, 2017 and 2016 , respectively. Time deposit accounts with balances of $250,000 or more totaled $2.3 billion and $2.1 billion at December 31, 2017 and 2016 , respectively. The following table presents maturities of time deposits as of December 31, 2017 (in thousands): Maturing in: 2018 $ 5,228,690 2019 630,719 2020 345,861 2021 101,715 2022 27,809 Thereafter 48 $ 6,334,842 Included in deposits at December 31, 2017 are public funds deposits of $2.6 billion and brokered deposits of $2.4 billion . Investment securities available for sale with a carrying value of $1.2 billion were pledged as security for public funds deposits at December 31, 2017 . Interest expense on deposits for the years ended December 31, 2017 , 2016 and 2015 was as follows (in thousands): 2017 2016 2015 Interest bearing demand $ 12,873 $ 8,343 $ 5,782 Money market 79,645 50,802 36,005 Savings 752 972 1,739 Time 77,663 59,656 47,625 $ 170,933 $ 119,773 $ 91,151

Deposits Deposits (Tables)

Deposits Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Summary of Average Balances and Weighted Average Rates Paid on Deposits	The following table presents average balances and weighted average rates paid on deposits for the years ended December 31, 2017 , 2016 and 2015 (dollars in thousands): 2017 2016 2015 Average Balance Average Rate Paid Average Balance Average Average Balance Average Demand deposits: Non-interest bearing $ 3,069,565 — % $ 2,968,192 — % $ 2,732,654 — % Interest bearing 1,586,390 0.81 % 1,382,717 0.60 % 1,169,921 0.49 % Money market 9,364,498 0.85 % 7,946,447 0.64 % 6,313,340 0.57 % Savings 365,603 0.21 % 415,205 0.23 % 536,026 0.32 % Time 6,094,336 1.27 % 5,326,630 1.12 % 4,305,857 1.11 % $ 20,480,392 0.83 % $ 18,039,191 0.66 % $ 15,057,798 0.61 %
Maturities of Time Deposits [Table Text Block]	The following table presents maturities of time deposits as of December 31, 2017 (in thousands): Maturing in: 2018 $ 5,228,690 2019 630,719 2020 345,861 2021 101,715 2022 27,809 Thereafter 48 $ 6,334,842
Schedule of Interest Expense on Deposits	Interest expense on deposits for the years ended December 31, 2017 , 2016 and 2015 was as follows (in thousands): 2017 2016 2015 Interest bearing demand $ 12,873 $ 8,343 $ 5,782 Money market 79,645 50,802 36,005 Savings 752 972 1,739 Time 77,663 59,656 47,625 $ 170,933 $ 119,773 $ 91,151

Federal Home Loan Bank Advanc37

Federal Home Loan Bank Advances and Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
FHLB Advances, Notes and Other Borrowings [Abstract]
Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block]	The following table presents information about outstanding FHLB advances as of December 31, 2017 (dollars in thousands): Range of Interest Rates Amount Minimum Maximum Weighted Average Rate Maturing in: 2018—One month or less $ 2,425,000 1.20 % 1.42 % 1.35 % 2018—Over one month 2,121,000 1.25 % 1.69 % 1.43 % 2019 100,000 1.46 % 1.57 % 1.52 % 2020 125,000 1.67 % 1.78 % 1.73 % Carrying value $ 4,771,000
Schedule of Debt [Table Text Block]	At December 31, 2017 and 2016 outstanding senior notes payable and other borrowings consisted of the following (dollars in thousands): 2017 2016 Principal amount of 4.875% senior notes $ 400,000 $ 400,000 Unamortized discount and debt issuance costs (6,275 ) (6,908 ) 393,725 393,092 Capital lease obligations 9,105 9,717 $ 402,830 $ 402,809

Federal Home Loan Bank Advanc38

Federal Home Loan Bank Advances, Notes and Other Borrowings Notes payable and other borrowings table (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block]	The following table presents information about outstanding FHLB advances as of December 31, 2017 (dollars in thousands): Range of Interest Rates Amount Minimum Maximum Weighted Average Rate Maturing in: 2018—One month or less $ 2,425,000 1.20 % 1.42 % 1.35 % 2018—Over one month 2,121,000 1.25 % 1.69 % 1.43 % 2019 100,000 1.46 % 1.57 % 1.52 % 2020 125,000 1.67 % 1.78 % 1.73 % Carrying value $ 4,771,000
Schedule of Debt [Table Text Block]	At December 31, 2017 and 2016 outstanding senior notes payable and other borrowings consisted of the following (dollars in thousands): 2017 2016 Principal amount of 4.875% senior notes $ 400,000 $ 400,000 Unamortized discount and debt issuance costs (6,275 ) (6,908 ) 393,725 393,092 Capital lease obligations 9,105 9,717 $ 402,830 $ 402,809

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The components of the provision (benefit) for income taxes for the years ended December 31, 2017 , 2016 and 2015 were as follows (in thousands): 2017 2016 2015 Current: Federal $ (251,880 ) $ 51,806 $ 18,230 State (15,733 ) 27,708 (2,468 ) (267,613 ) 79,514 15,762 Deferred: Federal 46,377 35,045 20,509 State 11,424 (4,856 ) 8,962 57,801 30,189 29,471 $ (209,812 ) $ 109,703 $ 45,233
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of expected income tax expense at the statutory federal income tax rate of 35% to the Company’s effective income tax rate for the years ended December 31, 2017 , 2016 and 2015 follows (dollars in thousands): 2017 2016 2015 Amount Percent Amount Percent Amount Percent Tax expense calculated at the statutory federal income tax rate $ 141,561 35.00 % $ 117,405 35.00 % $ 103,912 35.00 % Increases (decreases) resulting from: Income not subject to tax (29,511 ) (7.30 )% (23,215 ) (6.92 )% (14,279 ) (4.81 )% State income taxes, net of federal tax benefit 19,332 4.78 % 15,894 4.74 % 12,889 4.34 % Uncertain tax positions - lapse of statute of limitations (2,696 ) (0.66 )% — — % (6,166 ) (2.08 )% Discrete income tax benefit (327,945 ) (81.08 )% — — % (49,323 ) (16.61 )% Other, net (10,553 ) (2.61 )% (381 ) (0.12 )% (1,800 ) (0.60 )% $ (209,812 ) (51.87 )% $ 109,703 32.70 % $ 45,233 15.24 %
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The components of deferred tax assets and liabilities at December 31, 2017 and 2016 were as follows (in thousands): 2017 2016 Deferred tax assets: Excess of tax basis over carrying value of acquired loans $ 66,395 $ 130,004 Allowance for loan and lease losses 33,309 52,670 Net operating loss and tax credit carryforwards 15,892 11,641 Other 31,859 51,911 Gross deferred tax assets 147,455 246,226 Deferred tax liabilities: Net unrealized gains on investment securities available for sale 24,657 30,566 Lease financing, due to differences in depreciation 113,161 145,700 Other 13,468 7,020 Gross deferred tax liabilities 151,286 183,286 Net deferred tax asset (liability) $ (3,831 ) $ 62,940
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]	The Company has a liability for unrecognized tax benefits relating to uncertain state tax positions in several jurisdictions. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits for the years ended December 31, 2017 , 2016 and 2015 follows (in thousands): 2017 2016 2015 Balance, beginning of period $ 72,736 $ 43,412 $ 36,622 Additions for tax positions related to the current year 1,882 2,713 2,909 Additions for tax positions related to prior periods 1,661 25,168 11,618 Reductions due to changes in tax positions taken (15,316 ) — — Reductions due to settlements with taxing authorities — (200 ) (246 ) Reductions due to lapse of the statute of limitations (2,229 ) — (5,438 ) 58,734 71,093 45,465 Interest and penalties 486 1,643 (2,053 ) Balance, end of period $ 59,220 $ 72,736 $ 43,412

Derivatives and Hedging Activ40

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Contract Derivative Financial Instruments and Related Hedged Items	The following tables set forth certain information concerning the Company’s interest rate contract derivative financial instruments and related hedged items at December 31, 2017 and 2016 (dollars in thousands): 2017 Weighted Average Pay Rate Weighted Average Receive Rate Weighted Average Remaining Life in Years Notional Amount Balance Sheet Location Fair Value Hedged Item Asset Liability Derivatives designated as cash flow hedges: Pay-fixed interest rate swaps Variability of interest cash flows on variable rate borrowings 1.77% 3-Month Libor 4.3 $ 2,046,000 Other assets / Other liabilities $ 2,350 $ — Derivatives not designated as hedges: Pay-fixed interest rate swaps 3.87% Indexed to 1-month Libor 6.4 1,028,041 Other assets / Other liabilities 10,856 (13,173 ) Pay-variable interest rate swaps Indexed to 1-month Libor 3.87% 6.4 1,028,041 Other assets / Other liabilities 14,410 (12,189 ) Interest rate caps purchased, indexed to 1-month Libor 2.81% 1.3 145,354 Other assets 11 — Interest rate caps sold, indexed to 1-month Libor 2.81% 1.3 145,354 Other liabilities — (11 ) $ 4,392,790 $ 27,627 $ (25,373 ) 2016 Weighted Average Pay Rate Weighted Average Receive Rate Weighted Average Remaining Life in Years Notional Amount Balance Sheet Location Fair Value Hedged Item Asset Liability Derivatives designated as cash flow hedges: Pay-fixed interest rate swaps Variability of interest cash flows on variable rate borrowings 1.58% 3-Month Libor 3.3 $ 1,715,000 Other assets / Other liabilities $ 19,648 $ (3,112 ) Pay-fixed forward-starting interest rate swaps Variability of interest cash flows on variable rate borrowings 3.43% 3-Month Libor 10.5 300,000 Other liabilities — (27,866 ) Derivatives not designated as hedges: Pay-fixed interest rate swaps 3.77% Indexed to 1-month Libor 6.8 912,000 Other assets / Other liabilities 9,949 (20,383 ) Pay-variable interest rate swaps Indexed to 1-month Libor 3.77% 6.8 912,000 Other assets / Other liabilities 20,383 (9,949 ) Interest rate caps purchased, indexed to 1-month Libor 2.96% 2.3 189,057 Other assets 252 — Interest rate caps sold, indexed to 1-month Libor 2.96% 2.3 189,057 Other liabilities — (252 ) $ 4,217,114 $ 50,232 $ (61,562 )
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table provides information about the amount of loss reclassified from AOCI into interest expense for the years ended December 31, 2017 , 2016 and 2015 (dollars in thousands): Amount of Loss Reclassified from AOCI on Derivatives Location of Loss Reclassified from AOCI into Income 2017 2016 2015 Interest rate contracts $ (9,621 ) $ (16,161 ) $ (21,610 ) Interest expense on borrowings Interest rate contracts — — (4,869 ) Interest expense on deposits $ (9,621 ) $ (16,161 ) $ (26,479 )
Schedule of Interest Rate Swaps Subject to Master Netting Agreements	The Company does not offset assets and liabilities under master netting agreements for financial reporting purposes. Information on interest rate swaps subject to these agreements is as follows at December 31, 2017 and 2016 (in thousands): 2017 Gross Amounts Offset in Balance Net Amounts Presented in Gross Amounts Not Offset in Balance Sheet Gross Amounts Recognized Derivative Instruments Collateral Pledged Net Amount Derivative assets $ 13,217 $ — $ 13,217 $ (7,996 ) $ (5,221 ) $ — Derivative liabilities (13,173 ) — (13,173 ) 7,996 4,962 (215 ) $ 44 $ — $ 44 $ — $ (259 ) $ (215 ) 2016 Gross Amounts Offset in Balance Net Amounts Presented in Gross Amounts Not Offset in Balance Sheet Gross Amounts Recognized Derivative Instruments Collateral Pledged Net Amount Derivative assets $ 29,849 $ — $ 29,849 $ (27,485 ) $ — $ 2,364 Derivative liabilities (51,362 ) — (51,362 ) 27,485 23,796 (81 ) $ (21,513 ) $ — $ (21,513 ) $ — $ 23,796 $ 2,283

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Changes in AOCI	Changes in AOCI are summarized as follows for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Before Tax Tax Effect Net of Tax Unrealized gains on investment securities available for sale: Net unrealized holding gain arising during the period $ 49,131 $ (19,407 ) $ 29,724 Amounts reclassified to gain on investment securities available for sale, net (33,466 ) 13,219 (20,247 ) Net change in unrealized gains on investment securities available for sale 15,665 (6,188 ) 9,477 Unrealized losses on derivative instruments: Net unrealized holding loss arising during the period (2,577 ) 1,018 (1,559 ) Amounts reclassified to interest expense on borrowings 9,621 (3,800 ) 5,821 Net change in unrealized losses on derivative instruments 7,044 (2,782 ) 4,262 Other comprehensive income $ 22,709 $ (8,970 ) $ 13,739 2016 Before Tax Tax Effect Net of Tax Unrealized gains on investment securities available for sale: Net unrealized holding gain arising during the period $ 23,588 $ (9,317 ) $ 14,271 Amounts reclassified to gain on investment securities available for sale, net (14,461 ) 5,712 (8,749 ) Net change in unrealized gains on investment securities available for sale 9,127 (3,605 ) 5,522 Unrealized losses on derivative instruments: Net unrealized holding gain arising during the period 6,225 (2,459 ) 3,766 Amounts reclassified to interest expense on borrowings 16,161 (6,384 ) 9,777 Net change in unrealized losses on derivative instruments 22,386 (8,843 ) 13,543 Other comprehensive income $ 31,513 $ (12,448 ) $ 19,065 2015 Before Tax Tax Effect Net of Tax Unrealized gains on investment securities available for sale: Net unrealized holding loss arising during the period $ (34,470 ) $ 12,813 $ (21,657 ) Amounts reclassified to gain on investment securities available for sale, net (8,480 ) 3,350 (5,130 ) Net change in unrealized gains on investment securities available for sale (42,950 ) 16,163 (26,787 ) Unrealized losses on derivative instruments: Net unrealized holding loss arising during the period (22,635 ) 9,232 (13,403 ) Amounts reclassified to interest expense on deposits 4,869 (1,923 ) 2,946 Amounts reclassified to interest expense on borrowings 21,610 (8,536 ) 13,074 Net change in unrealized losses on derivative instruments 3,844 (1,227 ) 2,617 Other comprehensive loss $ (39,106 ) $ 14,936 $ (24,170 )
Schedule of the Categories of AOCI and Changes Therein	The categories of AOCI and changes therein are presented below for the years ended December 31, 2017 , 2016 and 2015 (in thousands): Unrealized Gains on Investment Securities Available for Sale Unrealized Losses on Derivative Instruments Total Balance at December 31, 2014 $ 68,322 $ (21,970 ) $ 46,352 Other comprehensive loss (26,787 ) 2,617 (24,170 ) Balance at December 31, 2015 $ 41,535 $ (19,353 ) $ 22,182 Other comprehensive income 5,522 13,543 19,065 Balance at December 31, 2016 $ 47,057 $ (5,810 ) $ 41,247 Other comprehensive income 9,477 4,262 13,739 Balance at December 31, 2017 $ 56,534 $ (1,548 ) $ 54,986

Equity Based Compensation (Tabl

Equity Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	The following table summarizes compensation cost related to equity based awards for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 2016 2015 Compensation cost of equity based awards: Unvested and restricted share awards $ 18,087 $ 16,885 $ 15,573 Executive share-based awards 3,416 1,482 294 Incentive awards 1,289 — — Total compensation cost of equity based awards 22,792 18,367 15,867 Related tax benefits (8,576 ) (6,899 ) (5,965 ) Compensation cost of equity based awards, net of tax $ 14,216 $ 11,468 $ 9,902
Schedule of Nonvested Share Activity [Table Text Block]	A summary of activity related to unvested share awards for the years ended December 31, 2017 , 2016 and 2015 follows: Number of Share Awards Weighted Average Grant Date Fair Value Unvested share awards outstanding, December 31, 2014 829,225 $ 30.06 Granted 664,928 32.06 Vested (394,498 ) 28.72 Canceled or forfeited (59,270 ) 29.82 Unvested share awards outstanding, December 31, 2015 1,040,385 31.86 Granted 651,760 31.00 Vested (428,167 ) 31.79 Canceled or forfeited (143,278 ) 31.31 Unvested share awards outstanding, December 31, 2016 1,120,700 31.46 Granted 621,806 40.24 Vested (553,007 ) 31.67 Canceled or forfeited (81,022 ) 34.51 Unvested share awards outstanding, December 31, 2017 1,108,477 $ 36.06 Unvested share awards are generally valued at the closing price of the Company's common stock on the date of grant. The following table summarizes the closing price of the Company's stock on the date of grant for shares granted and the aggregate grant date fair value of shares vesting during the years ended December 31, 2017 , 2016 , and 2015 (in thousands, except per share data): 2017 2016 2015 Range of the closing price on date of grant $33.21 - $40.84 $29.78 - $33.76 $31.35 - $38.63 Aggregate grant date fair value of shares vesting $ 17,514 $ 13,613 $ 11,330
Schedule of Other Share-based Compensation, Activity [Table Text Block]	A summary of activity related to executive share-based awards for the years ended December 31, 2017 and 2016 follows: RSU PSU Unvested executive share-based awards outstanding, December 31, 2015 — — Granted 97,852 57,873 Vested (19,291 ) — Unvested executive share-based awards outstanding, December 31, 2016 78,561 57,873 Granted 47,848 47,848 Vested (35,241 ) — Unvested executive share-based awards outstanding, December 31, 2017 91,168 105,721
Share-based Compensation, Stock Options, Activity [Table Text Block]	A summary of activity related to stock option awards for the years ended December 31, 2017 , 2016 and 2015 follows: Number of Option Awards Weighted Average Exercise Price Option awards outstanding, December 31, 2014 5,015,047 $ 26.49 Exercised (1,363,895 ) 26.14 Option awards outstanding, December 31, 2015 3,651,152 26.62 Exercised (47,979 ) 16.50 Canceled or forfeited (1,097 ) 63.74 Option awards outstanding, December 31, 2016 3,602,076 26.74 Exercised (2,331,388 ) 26.63 Option awards outstanding and exercisable, December 31, 2017 1,270,688 $ 26.93
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	There were no option awards granted during the years ended December 31, 2017 , 2016 and 2015 . Additional information about options outstanding and exercisable at December 31, 2017 is presented in the following table: Outstanding and Exercisable Options Range of Exercise Prices Number of Options Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) $11.14 13,160 1.73 $ 389 $15.94 - $19.97 29,145 2.59 672 $22.18 - $22.31 41,417 3.47 764 $27 1,170,847 3.08 16,064 $63.74 16,119 0.93 — 1,270,688 3.04 $ 17,889

Regulatory Requirements and R43

Regulatory Requirements and Restrictions (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	The following tables provide information regarding regulatory capital for the Company and the Bank as of December 31, 2017 and 2016 (dollars in thousands): 2017 Actual Required to be Considered Well Capitalized Required to be Considered Adequately Capitalized Amount Ratio Amount Ratio Amount Ratio BankUnited, Inc.: Tier 1 leverage $ 2,892,069 9.72 % N/A (1) N/A (1) $ 1,189,944 4.00 % CET1 risk-based capital $ 2,892,069 13.11 % $ 1,434,193 6.50 % $ 992,903 4.50 % Tier 1 risk-based capital $ 2,892,069 13.11 % $ 1,765,161 8.00 % $ 1,323,871 6.00 % Total risk based capital $ 3,041,004 13.78 % $ 2,206,451 10.00 % $ 1,765,161 8.00 % BankUnited: Tier 1 leverage $ 3,107,920 10.47 % $ 1,483,796 5.00 % $ 1,187,037 4.00 % CET1 risk-based capital $ 3,107,920 14.13 % $ 1,429,999 6.50 % $ 989,999 4.50 % Tier 1 risk-based capital $ 3,107,920 14.13 % $ 1,759,999 8.00 % $ 1,319,999 6.00 % Total risk based capital $ 3,255,221 14.80 % $ 2,199,999 10.00 % $ 1,759,999 8.00 % 2016 Actual Required to be Considered Well Capitalized Required to be Considered Adequately Capitalized Amount Ratio Amount Ratio Amount Ratio BankUnited, Inc.: Tier 1 leverage $ 2,298,450 8.41 % N/A (1) N/A (1) $ 1,092,921 4.00 % CET1 risk-based capital $ 2,298,450 11.63 % $ 1,284,498 6.50 % $ 889,268 4.50 % Tier 1 risk-based capital $ 2,298,450 11.63 % $ 1,580,921 8.00 % $ 1,185,691 6.00 % Total risk based capital $ 2,459,470 12.45 % $ 1,976,151 10.00 % $ 1,580,921 8.00 % BankUnited: Tier 1 leverage $ 2,534,402 9.30 % $ 1,361,959 5.00 % $ 1,089,567 4.00 % CET1 risk-based capital $ 2,534,402 12.89 % $ 1,278,277 6.50 % $ 884,961 4.50 % Tier 1 risk-based capital $ 2,534,402 12.89 % $ 1,573,265 8.00 % $ 1,179,948 6.00 % Total risk based capital $ 2,694,048 13.70 % $ 1,966,581 10.00 % $ 1,573,265 8.00 % (1) There is no Tier 1 leverage ratio component in the definition of a well-capitalized bank holding company.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present assets and liabilities measured at fair value on a recurring basis at December 31, 2017 and 2016 (in thousands): 2017 Level 1 Level 2 Level 3 Total Investment securities available for sale: U.S. Treasury securities $ 24,953 $ — $ — $ 24,953 U.S. Government agency and sponsored enterprise residential MBS — 2,058,027 — 2,058,027 U.S. Government agency and sponsored enterprise commercial MBS — 234,508 — 234,508 Private label residential MBS and CMOs — 576,033 52,214 628,247 Private label commercial MBS — 1,046,415 — 1,046,415 Single family rental real estate-backed securities — 562,706 — 562,706 Collateralized loan obligations — 723,681 — 723,681 Non-mortgage asset-backed securities — 121,747 — 121,747 Preferred stocks 63,543 — — 63,543 State and municipal obligations — 657,203 — 657,203 SBA securities — 550,682 — 550,682 Other debt securities — 3,791 5,329 9,120 Servicing rights — — 30,737 30,737 Derivative assets — 27,627 — 27,627 Total assets at fair value $ 88,496 $ 6,562,420 $ 88,280 $ 6,739,196 Derivative liabilities $ — $ 25,373 $ — $ 25,373 Total liabilities at fair value $ — $ 25,373 $ — $ 25,373 2016 Level 1 Level 2 Level 3 Total Investment securities available for sale: U.S. Treasury securities $ 5,005 $ — $ — $ 5,005 U.S. Government agency and sponsored enterprise residential MBS — 1,527,242 — 1,527,242 U.S. Government agency and sponsored enterprise commercial MBS — 124,586 — 124,586 Private label residential MBS and CMOs — 254,488 120,610 375,098 Private label commercial MBS — 1,187,624 — 1,187,624 Single family rental real estate-backed securities — 861,251 — 861,251 Collateralized loan obligations — 487,296 — 487,296 Non-mortgage asset-backed securities — 186,736 — 186,736 Preferred stocks 86,890 1,313 — 88,203 State and municipal obligations — 698,546 — 698,546 SBA securities — 523,906 — 523,906 Other debt securities — 3,519 4,572 8,091 Servicing rights — — 27,159 27,159 Derivative assets — 50,232 — 50,232 Total assets at fair value $ 91,895 $ 5,906,739 $ 152,341 $ 6,150,975 Derivative liabilities $ — $ 61,562 $ — $ 61,562 Total liabilities at fair value $ — $ 61,562 $ — $ 61,562
Reconciliation of the Changes in the Fair Value of Assets and Liabilities Measured on a Recurring Basis, Unobservable Input	The following tables reconcile changes in the fair value of assets and liabilities measured at fair value on a recurring basis and classified in level 3 of the fair value hierarchy during the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 120,610 $ 4,572 $ 27,159 Gains (losses) for the period included in: Net income 25,547 — (5,821 ) Other comprehensive income (27,569 ) 766 — Discount accretion 6,181 280 — Purchases or additions — — 9,399 Sales (45,524 ) — — Settlements (27,031 ) (289 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 52,214 $ 5,329 $ 30,737 2016 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 140,883 $ 4,532 $ 20,017 Gains (losses) for the period included in: Net income — — (6,023 ) Other comprehensive income (2,229 ) (9 ) — Discount accretion 5,947 116 — Purchases or additions — — 13,165 Settlements (23,991 ) (67 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 120,610 $ 4,572 $ 27,159 The following tables reconcile changes in the fair value of assets and liabilities measured at fair value on a recurring basis and classified in level 3 of the fair value hierarchy during the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 120,610 $ 4,572 $ 27,159 Gains (losses) for the period included in: Net income 25,547 — (5,821 ) Other comprehensive income (27,569 ) 766 — Discount accretion 6,181 280 — Purchases or additions — — 9,399 Sales (45,524 ) — — Settlements (27,031 ) (289 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 52,214 $ 5,329 $ 30,737 2016 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 140,883 $ 4,532 $ 20,017 Gains (losses) for the period included in: Net income — — (6,023 ) Other comprehensive income (2,229 ) (9 ) — Discount accretion 5,947 116 — Purchases or additions — — 13,165 Settlements (23,991 ) (67 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 120,610 $ 4,572 $ 27,159 2015 Private Label Residential MBS Other Debt Securities Servicing Rights Balance at beginning of period $ 168,077 $ 4,918 $ — Gains (losses) for the period included in: Net income — — (2,062 ) Other comprehensive income (7,469 ) (434 ) — Discount accretion 6,524 148 — Purchases or additions — — 13,610 Settlements (26,249 ) (100 ) — Transfers into level 3 — — — Transfers out of level 3 — — — Balance at end of period $ 140,883 $ 4,532 $ 11,548
Valuation Techniques and Unobservable Inputs Used in the Valuation of Financial Instruments Falling Within Level 3 of the Fair Value Hierarchy	The following table provides information about the valuation techniques and unobservable inputs used in the valuation of private label residential MBS and CMOs falling within level 3 of the fair value hierarchy as of December 31, 2017 (dollars in thousands): Fair Value at Valuation Technique Unobservable Input Range (Weighted Average) December 31, 2017 Investment grade $ 32,997 Discounted cash flow Voluntary prepayment rate 9.00% - 27.80% (16.94%) Probability of default 0.00% - 4.10% (1.18%) Loss severity 15.00% - 86.00% (30.56%) Discount rate 1.68% - 8.11% (3.64%) Non-investment grade $ 19,217 Discounted cash flow Voluntary prepayment rate 0.70% - 27.80% (15.37%) Probability of default 0.00% - 7.00% (2.00%) Loss severity 15.00% - 83.00% (31.04%) Discount rate 2.31% - 9.13% (6.03%) The significant unobservable inputs impacting the fair value measurement of private label residential MBS and CMOs include voluntary prepayment rates, probability of default, loss severity given default and discount rates. Generally, increases in probability of default, loss severity or discount rates would result in a lower fair value measurement. Alternatively, decreases in probability of default, loss severity or discount rates would result in a higher fair value measurement. For securities with less favorable credit characteristics, decreases in voluntary prepayment speeds may be interpreted as a deterioration in the overall credit quality of the underlying collateral and as such, lead to lower fair value measurements. The fair value measurements of those securities with higher levels of subordination will be less sensitive to changes in these unobservable inputs other than discount rates, while securities with lower levels of subordination will show a higher degree of sensitivity to changes in these unobservable inputs other than discount rates. Generally, a change in the assumption used for probability of default is accompanied by a directionally similar change in the assumption used for loss severity given default and a directionally opposite change in the assumption used for voluntary prepayment rate. The following table provides information about the valuation techniques and significant unobservable inputs used in the valuation of servicing rights as of December 31, 2017 (dollars in thousands): Fair Value at Valuation Technique Unobservable Input Range (Weighted Average) December 31, 2017 Residential MSRs $ 19,622 Discounted cash flow Prepayment rate 7.31% - 26.98% (12.12%) Discount rate 9.50% - 9.58% (9.51%) Commercial servicing rights $ 11,115 Discounted cash flow Prepayment rate 0.66% - 10.99% (8.79%) Discount rate 8.41% - 15.26% (12.69%)
Schedule of Assets for Which Nonrecurring Changes in Fair Value have been Recorded	The following tables present the carrying value of assets for which non-recurring changes in fair value have been recorded for the years ended December 31, 2017 , 2016 and 2015 (in thousands): 2017 Losses from Fair Value Changes Level 1 Level 2 Level 3 Total Years Ended OREO and repossessed assets $ — $ — $ 5,790 $ 5,790 $ (2,078 ) Impaired loans $ — $ — $ 93,051 $ 93,051 $ (65,716 ) 2016 Losses from Fair Value Changes Level 1 Level 2 Level 3 Total Years Ended OREO and repossessed assets $ — $ — $ 12,466 $ 12,466 $ (1,156 ) Impaired loans $ — $ — $ 78,121 $ 78,121 $ (25,573 ) Equipment under operating lease $ — — $ — $ 8,173 $ 8,173 $ (4,100 ) 2015 Losses from Fair Value Changes Level 1 Level 2 Level 3 Total Years Ended OREO and repossessed assets $ — $ — $ 7,389 $ 7,389 $ (1,206 ) Impaired loans $ — $ — $ 30,812 $ 30,812 $ (9,865 ) Residential MSRs $ — $ — $ 8,469 $ 8,469 $ (15 ) Included in the tables above are impaired taxi medallion loans with carrying values of $86.0 million and $50.7 million at December 31, 2017 and 2016 , respectively, the majority of which were in New York City. Losses of $62.4 million and $12.7 million were recognized on impaired taxi medallion loans during the years ended December 31, 2017 and 2016 , respectively. There were no impaired taxi medallion loans at December 31, 2015. In addition, OREO and repossessed assets reported above included repossessed taxi medallions with carrying values of $ 2.1 million and $2.5 million at December 31, 2017 and 2016 , respectively. Losses of $1.3 million and $0.2 million were recognized on repossessed taxi medallions during the years ended December 31, 2017 and 2016 , respectively. Decreases in the value of medallions are largely driven by decreases in revenues generated from the medallions. Inputs that had the most significant impact on the valuation of New York City taxi medallions at December 31, 2017 are presented below: Average Amount Average fare per trip $16.04 Number of trips per shift 15.3 Days worked per month 25.9 Second shift rental achievement 53.9 %
Schedule of the Carrying Value and Fair Value of Financial Instruments	The following table presents the carrying value and fair value of financial instruments and the level within the fair value hierarchy in which those measurements are classified at December 31, 2017 and 2016 (dollars in thousands): 2017 2016 Level Carrying Value Fair Value Carrying Value Fair Value Assets: Cash and cash equivalents 1 $ 194,582 $ 194,582 $ 448,313 $ 448,313 Investment securities available for sale 1/2/3 6,680,832 6,680,832 6,073,584 6,073,584 Investment securities held to maturity 3 10,000 10,000 10,000 10,000 Non-marketable equity securities 2 265,989 265,989 284,272 284,272 Loans held for sale 2 34,097 37,847 41,198 45,833 Loans: Covered 3 502,860 922,888 611,942 1,200,291 Non-covered 3 20,768,849 20,759,567 18,630,499 18,713,495 FDIC Indemnification asset 3 295,635 148,356 515,933 256,691 Derivative assets 2 27,627 27,627 50,232 50,232 Liabilities: Demand, savings and money market deposits 2 $ 15,543,637 $ 15,543,637 $ 13,735,248 $ 13,735,248 Time deposits 2 6,334,842 6,324,010 5,755,642 5,759,787 FHLB advances 2 4,771,000 4,774,160 5,239,348 5,244,188 Notes and other borrowings 2 402,830 435,361 402,809 403,733 Derivative liabilities 2 25,373 25,373 61,562 61,562

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of the Total Lending Related Commitments Outstanding	Total lending related commitments outstanding at December 31, 2017 were as follows (in thousands): Commitments to fund loans $ 376,525 Commitments to purchase loans 401,270 Unfunded commitments under lines of credit 2,278,201 Commercial and standby letters of credit 82,854 $ 3,138,850

Condensed Financial Statement46

Condensed Financial Statements of BankUnited, Inc. (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Statements [Abstract]
Condensed Balance Sheet [Table Text Block]	Condensed Balance Sheets December 31, 2017 December 31, 2016 Assets: Cash and cash equivalents $ 131,696 $ 87,718 Investment securities available for sale, at fair value 63,543 78,293 Investment in BankUnited, N.A. 3,239,717 2,652,535 Deferred tax asset, net 9,456 16,738 Other assets 8,462 5,345 Total assets $ 3,452,874 $ 2,840,629 Liabilities and Stockholders' Equity: Notes payable $ 393,725 $ 393,092 Other liabilities 33,087 29,108 Stockholders' equity 3,026,062 2,418,429 Total liabilities and stockholders' equity $ 3,452,874 $ 2,840,629
Condensed Income Statement [Table Text Block]	Condensed Statements of Income Years Ended December 31, 2017 2016 2015 Income: Interest and dividends on investment securities available for sale $ 3,580 $ 4,280 $ 4,866 Service fees from subsidiary 18,787 21,957 17,404 Equity in earnings of subsidiary 639,250 242,874 256,456 Other — — 235 Total 661,617 269,111 278,961 Expense: Interest on borrowings 20,132 20,100 2,457 Employee compensation and benefits 27,032 27,143 22,099 Other 5,047 4,466 4,356 Total 52,211 51,709 28,912 Income before income taxes 609,406 217,402 250,049 Benefit for income taxes (4,867 ) (8,339 ) (1,611 ) Net income $ 614,273 $ 225,741 $ 251,660
Condensed Cash Flow Statement [Table Text Block]	Condensed Statements of Cash Flows Years Ended December 31, 2017 2016 2015 Cash flows from operating activities: Net income $ 614,273 $ 225,741 $ 251,660 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (519,250 ) (157,374 ) (176,456 ) Equity based compensation 22,692 18,032 16,027 Other 3,343 7,438 1,878 Net cash provided by operating activities 121,058 93,837 93,109 Cash flows from investing activities: Capital contributions to subsidiary (55,000 ) — (575,000 ) Purchase of investment securities available for sale — (20,150 ) — Proceeds from repayments, sale, maturities and calls of investment securities available for sale 15,000 19,401 46,031 Other (250 ) (3 ) (285 ) Net cash used in investing activities (40,250 ) (752 ) (529,254 ) Cash flows from financing activities: Proceeds from issuance of notes payable — — 392,252 Dividends paid (91,628 ) (89,824 ) (88,981 ) Proceeds from exercise of stock options 62,095 791 35,647 Other (7,297 ) 856 1,593 Net cash provided by (used in) financing activities (36,830 ) (88,177 ) 340,511 Net increase (decrease) in cash and cash equivalents 43,978 4,908 (95,634 ) Cash and cash equivalents, beginning of period 87,718 82,810 178,444 Cash and cash equivalents, end of period $ 131,696 $ 87,718 $ 82,810 Supplemental schedule of non-cash investing and financing activities: Dividends declared, not paid $ 23,055 $ 22,510 $ 22,380

Quarterly Financial Informati47

Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Table Text Block]	Financial information by quarter for the years ended December 31, 2017 and 2016 follows (in thousands, except per share data): 2017 Fourth Quarter Third Quarter Second Quarter First Quarter Total Interest income $ 312,645 $ 309,443 $ 298,835 $ 283,538 $ 1,204,461 Interest expense 73,819 68,179 59,246 52,945 254,189 Net interest income before provision for loan losses 238,826 241,264 239,589 230,593 950,272 Provision for loan losses 5,174 37,854 13,619 12,100 68,747 Net interest income after provision for loan losses 233,652 203,410 225,970 218,493 881,525 Non-interest income 46,541 53,326 29,893 28,144 157,904 Non-interest expense 161,271 156,705 160,435 156,557 634,968 Income before income taxes 118,922 100,031 95,428 90,080 404,461 Provision (benefit) for income taxes (298,872 ) 32,252 29,021 27,787 (209,812 ) Net income $ 417,794 $ 67,779 $ 66,407 $ 62,293 $ 614,273 Earnings per common share, basic $ 3.80 $ 0.62 $ 0.60 $ 0.57 $ 5.60 Earnings per common share, diluted $ 3.79 $ 0.62 $ 0.60 $ 0.57 $ 5.58 2016 Fourth Quarter Third Quarter Second Quarter First Quarter Total Interest income $ 277,965 $ 269,981 $ 260,464 $ 250,807 $ 1,059,217 Interest expense 50,466 48,246 46,154 43,966 188,832 Net interest income before provision for loan losses 227,499 221,735 214,310 206,841 870,385 Provision for loan losses 8,462 24,408 14,333 3,708 50,911 Net interest income after provision for loan losses 219,037 197,327 199,977 203,133 819,474 Non-interest income 29,287 25,075 28,857 23,198 106,417 Non-interest expense 156,223 148,004 144,112 142,108 590,447 Income before income taxes 92,101 74,398 84,722 84,223 335,444 Provision (benefit) for income taxes 28,807 23,550 27,997 29,349 109,703 Net income $ 63,294 $ 50,848 $ 56,725 $ 54,874 $ 225,741 Earnings per common share, basic $ 0.59 $ 0.47 $ 0.53 $ 0.51 $ 2.11 Earnings per common share, diluted $ 0.59 $ 0.47 $ 0.52 $ 0.51 $ 2.09 Earnings for the fourth quarter 2017 benefited from a discrete income tax benefit of $327.9 million . See Note 11 to the consolidated financial statements for more information about the discrete income tax benefits.

Earnings Per Common Share (Comp

Earnings Per Common Share (Computation of Basic and Diluted Earnings per Common Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net income	$ 417,794	$ 67,779	$ 66,407	$ 62,293	$ 63,294	$ 50,848	$ 56,725	$ 54,874	$ 614,273	$ 225,741	$ 251,660
Distributed and undistributed earnings allocated to participating securities									(23,250)	(8,760)	(9,742)
Income allocated to common stockholders for basic earnings per common share									$ 591,023	$ 216,981	$ 241,918
Denominator:
Weighted average common shares outstanding									106,574,448	104,097,182	103,187,530
Less average unvested stock awards									(1,104,035)	(1,157,378)	(1,128,416)
Weighted average shares for basic earnings per common share									105,470,413	102,939,804	102,059,114
Basic earnings per common share	$ 3.80	$ 0.62	$ 0.60	$ 0.57	$ 0.59	$ 0.47	$ 0.53	$ 0.51	$ 5.60	$ 2.11	$ 2.37
Numerator:
Income allocated to common stockholders for basic earnings per common share									$ 591,023	$ 216,981	$ 241,918
Adjustment for earnings reallocated from participating securities									(263)	62	54
Income used in calculating diluted earnings per common share									$ 590,760	$ 217,043	$ 241,972
Denominator:
Weighted average shares for basic earnings per common share									105,470,413	102,939,804	102,059,114
Dilutive effect of stock options									387,074	716,366	913,036
Weighted average shares for diluted earnings per common share									105,857,487	103,656,170	102,972,150
Diluted earnings per common share	$ 3.79	$ 0.62	$ 0.60	$ 0.57	$ 0.59	$ 0.47	$ 0.52	$ 0.51	$ 5.58	$ 2.09	$ 2.35

Basis of Presentation and Sum49

Basis of Presentation and Summary of Significant Accounting Policies (Narrative) (Details)	May 21, 2009USD ($)	Dec. 31, 2017USD ($)countybranchbanking_centersubsidiarybank$ / shares	Dec. 31, 2016USD ($)
Summary of Significant Accounting Policies [Line Items]
Number Of Subsidiaries | subsidiary		1
Number of branches located in Florida (in Branches) | branch		87
Number of Florida counties with branches (in counties) | county		15
Number of branches located in New York metropolitan area (in Branches) | banking_center		6
Number of loss sharing agreements	2
Percent FDIC will reimburse for covered losses (in Percent)	80.00%
Limit on losses reimbursed at 80%	$ 4,000,000,000
Percent of losses in excess of limit FDIC will reimburse (in Percent)	95.00%
Period of delinquency of principal or interest at which commercial loans are placed on non-accrual status unless the loan is well-secured and in the process of collection.		90 days
Period of delinquency of interest at which residential and consumer loans, other than ACI loans, are placed on non-accrual status unless the loan is well-secured and in the process of collection.		90 days
Period of principal or interest paid at which residential loans are returned to accrual status.		90 days
Maximum period of loans past due reported as current (in Duration)		30 days
Minimum period of delinquency for non-covered loans secured by residential real estate, at which an assessment of collateral value is made (in Duration)		120 days
Maximum period of delinquency at which any residential loan balance in excess of fair value less cost to sell is charged off (in Duration)		180 days
Period after receipt of notification of filing from the bankruptcy court at which any outstanding balance in excess of fair value of collateral less cost to sell, at which it is charged off (in Duration)		60 days
Period within determination of loss if all borrowers are deceased, at which any outstanding balance in excess of fair value of collateral less cost to sell, at which it is charged off (in Duration)		60 days
Period within days of discovery of fraudulent activity, at which any outstanding balance in excess of fair value of collateral less cost to sell, at which it is charged off (in Duration)		90 days
Period of delinquency of consumer loans, at which, at which they are charged off when management deems them to be uncollectible (in Duration)		120 days
Loans and Leases Receivable, Net Charge-Off Rate Calculation, Banks Used In Assumption | bank		27
Goodwill		$ 78,000,000	$ 78,000,000
Fees and Commissions, Depositor Accounts		13,000,000
Investment securities available for sale, at fair value		6,680,832,000	6,073,584,000
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		98,906,000	103,806,000
Accounting Standards Update 2016-09 [Member]
Summary of Significant Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income		$ 3,700,000
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Basic Earnings Per Share | $ / shares		$ 0.03
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share | $ / shares		$ 0.03
Accounting Standards Update 2016-01 [Member]
Summary of Significant Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 2,200,000
Accounting Standards Update 2018-02 [Domain]
Summary of Significant Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		11,700,000
Preferred stocks
Summary of Significant Accounting Policies [Line Items]
Investment securities available for sale, at fair value		63,543,000	88,203,000
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		$ 3,631,000	$ 12,027,000
Building and Building Improvements [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		30 years
Leasehold Improvements [Member] | Minimum
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Leasehold Improvements [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		20 years
Furniture, Fixtures And Equipment [Member] | Minimum
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Furniture, Fixtures And Equipment [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		7 years
Computer Equipment [Member] | Minimum
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		3 years
Computer Equipment [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Software and Software Development Costs [Member] | Minimum
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		3 years
Software and Software Development Costs [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Commercial
Summary of Significant Accounting Policies [Line Items]
The value below which non accrual status commercial relationships may be evaluated for impairment at management's discretion		$ 1,000,000
Commercial | Minimum
Summary of Significant Accounting Policies [Line Items]
The value at which non accrual status commercial relationships are evaluated for impairment		$ 1,000,000
NEW YORK
Summary of Significant Accounting Policies [Line Items]
Loans and Leases Receivable, Net Charge-Off Rate Calculation, Banks Used In Assumption | bank		2

Earnings Per Common Share (Pote

Earnings Per Common Share (Potentially Dilutive Securities Outstanding) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Unvested shares and share units
Antidilutive Securities Excluded from Computation of Earnings per Share [Line Items]
Potentially dilutive securities outstanding (in Shares)	1,431,761	1,303,208	1,040,385
Stock options and warrants
Antidilutive Securities Excluded from Computation of Earnings per Share [Line Items]
Potentially dilutive securities outstanding (in Shares)	1,850,279	1,850,279	1,851,376

Earnings Per Common Share Earni

Earnings Per Common Share Earnings per Common Share (Narrative) (Details)	Dec. 31, 2017shares
Earnings Per Share [Abstract]
Dividend Equivalent Rights	3,023,314

Acquisition Activity (Narrative

Acquisition Activity (Narrative) (Details) - USD ($) $ in Thousands	May 01, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Consideration issued	$ 277,553	$ 0	$ 0	$ 277,553

Acquisition Activity (Schedule

Acquisition Activity (Schedule of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	May 01, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Other assets	$ 4,397
Total assets	270,767
Total liabilities	3,620
Estimated fair value of net assets acquired	267,147
Consideration issued	277,553	$ 0	$ 0	$ 277,553
Excess of consideration issued over fair value of net assets acquired	10,406
Loans held for investment
Business Acquisition [Line Items]
Loans	173,809
Loans held for sale
Business Acquisition [Line Items]
Loans	82,143
Commercial Servicing Rights [Member]
Business Acquisition [Line Items]
Servicing rights	$ 10,418

Investment Securities (Schedule

Investment Securities (Schedule of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 6,587,786	$ 5,996,203
Gross Unrealized Gains	98,906	103,806
Gross Unrealized Losses	(5,860)	(26,425)
Investment securities available for sale, at fair value	6,680,832	6,073,584
U.S. Treasury securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	24,981	4,999
Gross Unrealized Gains	0	6
Gross Unrealized Losses	(28)	0
Investment securities available for sale, at fair value	24,953	5,005
U.S. Government agency and sponsored enterprise residential MBS
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,043,373	1,513,028
Gross Unrealized Gains	16,094	15,922
Gross Unrealized Losses	(1,440)	(1,708)
Investment securities available for sale, at fair value	2,058,027	1,527,242
U.S. Government agency and sponsored enterprise commercial MBS
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	233,522	126,754
Gross Unrealized Gains	1,330	670
Gross Unrealized Losses	(344)	(2,838)
Investment securities available for sale, at fair value	234,508	124,586
Private label residential mortgage-backed securities and CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	613,732	334,167
Gross Unrealized Gains	16,473	42,939
Gross Unrealized Losses	(1,958)	(2,008)
Investment securities available for sale, at fair value	628,247	375,098
Private label commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,033,022	1,180,386
Gross Unrealized Gains	13,651	9,623
Gross Unrealized Losses	(258)	(2,385)
Investment securities available for sale, at fair value	1,046,415	1,187,624
Single family rental real estate-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	559,741	858,339
Gross Unrealized Gains	3,823	4,748
Gross Unrealized Losses	(858)	(1,836)
Investment securities available for sale, at fair value	562,706	861,251
Collateralized loan obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	720,429	487,678
Gross Unrealized Gains	3,252	868
Gross Unrealized Losses	0	(1,250)
Investment securities available for sale, at fair value	723,681	487,296
Non-mortgage asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	119,939	187,660
Gross Unrealized Gains	1,808	2,002
Gross Unrealized Losses	0	(2,926)
Investment securities available for sale, at fair value	121,747	186,736
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	59,912	76,180
Gross Unrealized Gains	3,631	12,027
Gross Unrealized Losses	0	(4)
Investment securities available for sale, at fair value	63,543	88,203
State and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	640,511	705,884
Gross Unrealized Gains	17,606	3,711
Gross Unrealized Losses	(914)	(11,049)
Investment securities available for sale, at fair value	657,203	698,546
SBA securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	534,534	517,129
Gross Unrealized Gains	16,208	7,198
Gross Unrealized Losses	(60)	(421)
Investment securities available for sale, at fair value	550,682	523,906
Other debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,090	3,999
Gross Unrealized Gains	5,030	4,092
Gross Unrealized Losses	0	0
Investment securities available for sale, at fair value	$ 9,120	$ 8,091

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)security	Dec. 31, 2015security
Schedule of Available-for-sale Securities [Line Items]
Number of held-to-maturity securities	1	1
Investment securities held to maturity | $	$ 10,000	$ 10,000
Weighted average life of investment portfolio (in Duration)	4 years 10 months 24 days
Effective duration of investment portfolio (in Duration)	1 year 8 months 9 days
Available-for-sale Securities Pledged as Collateral | $	$ 2,600,000	$ 1,800,000
Number of securities determined to be other than temporarily impaired during the period (in Securities)	0		0
Number of securities in unrealized loss positions (in Securities)	71
Number of securities which impairment considered insignificant (in Securities)	28
Available-for-sale securities, gross unrealized loss, considered insignificant | $	$ 277
US Treasury securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	1
U.S. Government agency and sponsored enterprise residential MBS
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	11
U.S. Government agency and sponsored enterprise commercial MBS
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	3
US Government Agencies and sponsored enterprise MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of fixed-rate securities in unrealized loss positions	8
Number of variable-rate securities in unrealized loss positions	6
Unrealized loss as a percent of amortized cost on securities in continuous unrealized loss positions (or less, less than)	3.00%
Private label residential mortgage-backed securities and CMOs
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	12
Private label commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities determined to be other than temporarily impaired during the period (in Securities)		2
Number of securities in unrealized loss positions (in Securities)	3
Single family rental real estate-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	6
State and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	6
SBA securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities in unrealized loss positions (in Securities)	1
Maximum [Member] | US Government Agencies and sponsored enterprise MBS [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss as a percent of amortized cost on securities in continuous unrealized loss positions (or less, less than)	1.00%
Maximum [Member] | Private label residential mortgage-backed securities and CMOs
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss as a percent of amortized cost on securities in continuous unrealized loss positions (or less, less than)	2.00%
Maximum [Member] | Private label commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss as a percent of amortized cost on securities in continuous unrealized loss positions (or less, less than)	1.00%
Maximum [Member] | Single family rental real estate-backed securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss as a percent of amortized cost on securities in continuous unrealized loss positions (or less, less than)	2.00%
Maximum [Member] | State and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Unrealized loss as a percent of amortized cost on securities in continuous unrealized loss positions (or less, less than)	3.00%

Investment Securities (Schedu56

Investment Securities (Schedule of Maturities of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 663,592
Due after one year through five years, Amortized Cost	3,196,717
Due after five years through ten years, Amortized Cost	2,229,852
Due after ten years, Amortized Cost	437,713
Preferred stocks with no stated maturity	59,912
Amortized Cost	6,587,786	$ 5,996,203
Due in one year or less, Fair Value	674,291
Due after one year through five years, Fair Value	3,232,157
Due after five years through ten years, Fair Value	2,264,131
Due after ten years, Fair Value	446,710
Preferred Stocks with no stated maturity, Fair Value	63,543
Fair Value	$ 6,680,832	$ 6,073,584

Investment Securities (Schedu57

Investment Securities (Schedule of Gains and Losses on the Sale and Exchange of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Proceeds from sale of investment securities available for sale	$ 1,287,591	$ 1,127,983	$ 1,114,020
Gross realized gains	37,530	14,924	8,955
Gross realized losses	(4,064)	0	(475)
Net realized gain	33,466	14,924	8,480
OTTI	0	(463)	0
Gain on investment securities available for sale, net	$ 33,466	$ 14,461	$ 8,480

Investment Securities (Schedu58

Investment Securities (Schedule of the Aggregate Fair Value and Amount by which Amortized Cost Exceeds Fair Value for Investment Securities that are in Unrealized Loss Positions) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 1,080,493	$ 1,383,990
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(4,546)	(22,752)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	94,520	515,566
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,314)	(3,673)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,175,013	1,899,556
Gross Unrealized Losses	(5,860)	(26,425)
U.S. Treasury securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	24,953
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(28)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	24,953
Gross Unrealized Losses	(28)	0
U.S. Government agency and sponsored enterprise residential MBS
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	471,120	191,463
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,141)	(628)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	13,028	112,391
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(299)	(1,080)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	484,148	303,854
Gross Unrealized Losses	(1,440)	(1,708)
U.S. Government agency and sponsored enterprise commercial MBS
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	26,265	89,437
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(344)	(2,838)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	26,265	89,437
Gross Unrealized Losses	(344)	(2,838)
Private label residential mortgage-backed securities and CMOs
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	330,068	122,142
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,858)	(1,680)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	5,083	8,074
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(100)	(328)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	335,151	130,216
Gross Unrealized Losses	(1,958)	(2,008)
Private label commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	81,322	169,535
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(258)	(2,370)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	24,985
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	(15)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	81,322	194,520
Gross Unrealized Losses	(258)	(2,385)
Single family rental real estate-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	94,750	139,867
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(858)	(842)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	176,057
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	(994)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	94,750	315,924
Gross Unrealized Losses	(858)	(1,836)
Collateralized loan obligations
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		69,598
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(402)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		173,983
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(848)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		243,581
Gross Unrealized Losses	0	(1,250)
Non-mortgage asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		139,477
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(2,926)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		139,477
Gross Unrealized Losses	0	(2,926)
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		10,087
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		10,087
Gross Unrealized Losses	0	(4)
State and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	30,715	448,180
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(49)	(11,049)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	60,982	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(865)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	91,697	448,180
Gross Unrealized Losses	(914)	(11,049)
SBA securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	21,300	4,204
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(10)	(13)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	15,427	20,076
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(50)	(408)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	36,727	24,280
Gross Unrealized Losses	$ (60)	$ (421)

Loans and Allowance for Loan 59

Loans and Allowance for Loan and Lease Losses (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Investment Past Due [Line Items]
Capital Leases, Net Investment in Direct Financing Leases	$ 738,220	$ 642,731
Purchases of loans	1,300,996	1,266,097	$ 787,834
Unpaid principal balance of real estate loans pledged as security for FHLB advances	10,500,000
Recorded investment of real estate loans pledged as security for FHLB advances	10,000,000
Unpaid principal balance of ACI loans	1,100,000	1,500,000
Impaired Financing Receivable, Interest Income, Accrual Method	9,600
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	4,100	3,500
1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Purchases of loans	$ 1,300,996	$ 1,266,097
Percent of loans by state	100.00%	100.00%
Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Impaired ACI Commercial Real Estate loans, with No Related Allowance, Recorded Investment	$ 22,002	$ 16,834
Commercial Lending Subsidiaries
Financing Receivable Investment Past Due [Line Items]
Capital Leases, Net Investment in Direct Financing Leases	738,000	643,000
Impaired ACI Commercial Real Estate loans, with No Related Allowance, Recorded Investment	0	10,620
Residential and Other Consumer
Financing Receivable Investment Past Due [Line Items]
Mortgage Loans in Process of Foreclosure, Amount	11,000	8,000
Non-Covered [Domain]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	1,900	1,600
Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Impaired ACI Commercial Real Estate loans, with No Related Allowance, Recorded Investment	$ 120	$ 0
Percent of loans by state	100.00%	100.00%
ACI loans | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Impaired ACI Commercial Real Estate loans, with No Related Allowance, Recorded Investment	$ 0	$ 1,300
ACI loans | Residential and Other Consumer
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		16,000
ACI Loans, Covered [Member] | Residential and Other Consumer
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	18,000
Covered [Member] | Residential and Other Consumer
Financing Receivable Investment Past Due [Line Items]
Other Real Estate, Foreclosed Assets, and Repossessed Assets	3,000	$ 5,000
Minimum | Commercial
Financing Receivable Investment Past Due [Line Items]
Financing receivable credit quality indicator, the value at which relationships are reevaluated at least annually	1,000
Maximum [Member] | Commercial
Financing Receivable Investment Past Due [Line Items]
Financing receivable credit quality indicator, the value at which relationships are reevaluated at least annually	$ 3,000
Florida [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Percent of loans by state	17.80%	19.50%
Florida [Member] | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Percent of loans by state	13.20%	14.00%
Florida [Member] | Non-Covered [Domain] | Commercial
Financing Receivable Investment Past Due [Line Items]
Percent of loans by state	43.40%	43.10%
New York [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Percent of loans by state	19.00%	19.30%
New York [Member] | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Percent of loans by state	20.90%	22.00%
New York [Member] | Non-Covered [Domain] | Commercial
Financing Receivable Investment Past Due [Line Items]
Percent of loans by state	36.40%	39.20%

Loans and Allowance for Loan 60

Loans and Allowance for Loan and Lease Losses (Schedule of Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 20,865,221	$ 18,732,711
Loans, gross	21,371,487	19,353,257
Non-covered premiums, discounts and deferred fees and costs, net	48,165	48,641
Premiums, discounts and deferred fees and costs, net	45,017	42,137
Non-covered loans, net of premiums, discounts and deferred fees and costs	20,913,386	18,781,352
Covered loans net of premiums, discounts and deferred fees and costs	503,118	614,042
Loans net of premiums, discounts and deferred fees and costs	21,416,504	19,395,394
Non-covered Allowance for loan and lease losses	(144,537)	(150,853)
Allowance for loan and lease losses	(144,795)	(152,953)
Non-covered loans, net	20,768,849	18,630,499
Loans, net	$ 21,271,709	$ 19,242,441
Percent of Total	100.00%	100.00%
1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 4,116,814	$ 3,422,425
Loans, gross	4,622,719	3,991,448
Loans net of premiums, discounts and deferred fees and costs	$ 4,676,710	$ 4,033,502
Percent of Total	21.60%	20.60%
Home equity loans and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 1,654	$ 1,120
Loans, gross	$ 2,015	$ 52,643
Percent of Total	0.00%	0.30%
Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 20,512	$ 24,365
Loans, gross	20,512	24,365
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 20,473	$ 24,306
Percent of Total	0.10%	0.10%
Residential and Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 4,138,980	$ 3,447,910
Loans, gross	$ 4,645,246	$ 4,068,456
Percent of Total	21.70%	21.00%
Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 3,215,697	$ 3,824,973
Loans, gross	3,215,697	3,824,973
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 3,218,953	$ 3,829,674
Percent of Total	15.00%	19.80%
Commercial real estate, Non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 4,485,276	$ 3,739,235
Loans, gross	4,485,276	3,739,235
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 4,474,801	$ 3,731,808
Percent of Total	21.00%	19.30%
Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 310,999	$ 311,436
Loans, gross	310,999	311,436
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 310,484	$ 310,913
Percent of Total	1.50%	1.60%
Commercial real estate, Owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 2,014,908	$ 1,736,858
Loans, gross	2,014,908	1,736,858
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 2,012,742	$ 1,735,850
Percent of Total	9.40%	9.00%
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 4,145,785	$ 3,391,614
Loans, gross	$ 4,145,785	$ 3,391,614
Percent of Total	19.40%	17.50%
Commercial Lending Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 2,553,576	$ 2,280,685
Loans, gross	2,553,576	2,280,685
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 2,562,499	$ 2,290,194
Percent of Total	12.00%	11.80%
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	$ 16,726,241	$ 15,284,801
Loans, gross	16,726,241	15,284,801
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 16,717,306	$ 15,285,577
Percent of Total	78.30%	79.00%
ACI Loans, Non-Covered
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 33,776	$ 46,945
ACI Loans, Non-Covered | Residential and Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	7
ACI Loans, Non-Covered | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, gross	34,000	47,000
Non-covered loans, net of premiums, discounts and deferred fees and costs	33,776	46,938
ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	479,068	536,242
Covered loans net of premiums, discounts and deferred fees and costs	479,068	536,242
Covered Allowance for loan and lease losses	0	0
Covered loans, net	479,068	536,242
ACI Loans, Covered [Member] | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	479,068	532,348
Covered loans net of premiums, discounts and deferred fees and costs	479,068	532,348
ACI Loans, Covered [Member] | Home equity loans and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	0	3,894
Covered loans net of premiums, discounts and deferred fees and costs	0	3,894
ACI Loans, Covered [Member] | Residential and Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	479,068	536,242
Non-ACI
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	27,198	84,304
Covered premiums, discounts and deferred fees and costs, net	(3,148)	(6,504)
Covered loans net of premiums, discounts and deferred fees and costs	24,050	77,800
Covered Allowance for loan and lease losses	(258)	(2,100)
Covered loans, net	23,792	75,700
Non-ACI | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	26,837	36,675
Covered loans net of premiums, discounts and deferred fees and costs	23,689	30,805
Non-ACI | Home equity loans and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	361	47,629
Covered loans net of premiums, discounts and deferred fees and costs	361	46,995
Non-ACI | Residential and Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans, gross	$ 27,198	$ 84,304

Loans and Allowance for Loan 61

Loans and Allowance for Loan and Lease Losses Loans and Allowance for Loan and Lease Losses (Direct Financing Leases) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Capital Leases, Future Minimum Payments Receivable, Next Twelve Months	$ 189,017
Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received	792,064	$ 689,631
Capital Leases, Net Investment in Direct Financing Leases, Unguaranteed Residual Values of Leased Property	17,872	3,704
Capital Leases, Net Investment in Direct Financing Leases, Gross Investment	809,936	693,335
Capital Leases, Net Investment in Direct Financing Leases, Deferred Income	76,900	55,891
Capital Leases, Net Investment in Direct Financing Leases, Initial Direct Costs	5,184	5,287
Capital Leases, Net Investment in Direct Financing Leases	738,220	$ 642,731
Capital Leases, Future Minimum Payments, Receivable in Two Years	158,846
Capital Leases, Future Minimum Payments, Receivable in Three Years	121,930
Capital Leases, Future Minimum Payments, Receivable in Four Years	74,536
Capital Leases, Future Minimum Payments, Receivable in Five Years	49,781
Capital Leases, Future Minimum Payments, Receivable Thereafter	$ 197,954

Loans and Allowance for Loan 62

Loans and Allowance for Loan and Lease Losses (Schedule for Accretable Yield Rollforward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ACI loans
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Beginning Balance	$ 675,385	$ 902,565	$ 1,005,312
Reclassifications from non-accretable difference	81,501	76,751	192,291
Accretion	(301,827)	(303,931)	(295,038)
Ending Balance	455,059	$ 675,385	$ 902,565
Home equity loans and lines of credit | ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Accretable Yield in pool of loans sold	$ 16,300

Loans and Allowance for Loan 63

Loans and Allowance for Loan and Lease Losses (Schedule of Sold Covered Residential Loans to Third Parties on a Non-recourse Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain (Loss) on Sale of Covered Loans	$ 27,589	$ (4,406)	$ 40,633
Gain (loss) on FDIC indemnification, net	(1,523)	11,615	(28,051)
Covered [Member] | Residential and Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
UPB of loans sold	203,970	241,348	249,038
Cash proceeds, net of transaction costs	169,828	171,367	207,425
Recorded investment in loans sold	152,422	185,837	172,496
Gain (Loss) on Sale of Covered Loans	$ 17,406	$ (14,470)	$ 34,929

Loans and Allowance for Loan 64

Loans and Allowance for Loan and Lease Losses (Allowance for Credit Losses on Financing Receivables) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses	$ 5,174	$ 37,854	$ 13,619	$ 12,100	$ 8,462	$ 24,408	$ 14,333	$ 3,708	$ 68,747	$ 50,911	$ 44,311
Charge-offs									(81,193)	(27,110)	(15,399)
Recoveries									4,288	3,324	1,374
Financing Receivable, Allowance for Credit Losses	144,795				152,953				144,795	152,953	125,828	$ 95,542
Loans net of premiums, discounts and deferred fees and costs	21,416,504				19,395,394				21,416,504	19,395,394
Covered loans net of premiums, discounts and deferred fees and costs	503,118				614,042				503,118	614,042
Non-covered loans, net of premiums, discounts and deferred fees and costs	20,913,386				18,781,352				20,913,386	18,781,352
Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									2,452	(3,446)	6,305
Charge-offs									(3,328)	(1,368)	(1,680)
Recoveries									93	106	71
Financing Receivable, Allowance for Credit Losses	10,720				11,503				10,720	11,503	16,211	11,515
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									66,295	54,357	38,006
Charge-offs									(77,865)	(25,742)	(13,719)
Recoveries									4,195	3,218	1,303
Financing Receivable, Allowance for Credit Losses	134,075				141,450				134,075	141,450	109,617	$ 84,027
Non-covered loans, net of premiums, discounts and deferred fees and costs	16,717,306				15,285,577				16,717,306	15,285,577
ACI Loans, Non-covered
Allowance for Loan and Lease Losses [Roll Forward]
Non-covered loans, net of premiums, discounts and deferred fees and costs	33,776				46,945				33,776	46,945
ACI Loans, Non-covered | Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0				7				0	7
ACI Loans, Non-covered | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Non-covered loans, net of premiums, discounts and deferred fees and costs	33,776				46,938				33,776	46,938
Covered [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									1,358	(1,681)	2,251
Charge-offs									(3,327)	(1,216)	(1,680)
Recoveries									127	129	105
Financing Receivable, Allowance for Credit Losses	258				2,100				258	2,100
Covered loans net of premiums, discounts and deferred fees and costs	503,118				614,042				503,118	614,042
Covered [Member] | Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									1,418	(1,632)	2,317
Charge-offs									(3,327)	(1,216)	(1,680)
Recoveries									67	80	39
Financing Receivable, Allowance for Credit Losses	258				2,100				258	2,100
Covered loans net of premiums, discounts and deferred fees and costs	503,118				614,042				503,118	614,042
Covered [Member] | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									(60)	(49)	(66)
Charge-offs									0	0	0
Recoveries									60	49	66
Financing Receivable, Allowance for Credit Losses	0				0				0	0
Covered loans net of premiums, discounts and deferred fees and costs	0				0				0	0
Covered [Member] | ACI loans
Allowance for Loan and Lease Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	0				0				0	0
Loans net of premiums, discounts and deferred fees and costs	479,068				536,242				479,068	536,242
Covered [Member] | ACI loans | Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	0				0				0	0
Loans net of premiums, discounts and deferred fees and costs	479,068				536,242				479,068	536,242
Covered [Member] | ACI loans | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Financing Receivable, Allowance for Credit Losses	0				0				0	0
Loans net of premiums, discounts and deferred fees and costs	0				0				0	0
Covered [Member] | Non-ACI loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance, balance, loans individually evaluated for impairment	118				529				118	529
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	140				1,571				140	1,571
Loans individually evaluated for impairment, balance	2,221				12,396				2,221	12,396
Loans collectively evaluated for impairment, balance	21,829				65,404				21,829	65,404
Covered [Member] | Non-ACI loans [Member] | Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Allowance, balance, loans individually evaluated for impairment	118				529				118	529
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	140				1,571				140	1,571
Loans individually evaluated for impairment, balance	2,221				12,396				2,221	12,396
Loans collectively evaluated for impairment, balance	21,829				65,404				21,829	65,404
Covered [Member] | Non-ACI loans [Member] | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Allowance, balance, loans individually evaluated for impairment	0				0				0	0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	0				0				0	0
Loans individually evaluated for impairment, balance	0				0				0	0
Loans collectively evaluated for impairment, balance	0				0				0	0
Non-Covered [Domain]
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									67,389	52,592	42,060
Charge-offs									(77,866)	(25,894)	(13,719)
Recoveries									4,161	3,195	1,269
Financing Receivable, Allowance for Credit Losses	144,537				150,853				144,537	150,853
Allowance, balance, loans individually evaluated for impairment	18,839				19,241				18,839	19,241
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	125,698				131,612				125,698	131,612
Loans individually evaluated for impairment, balance	174,940				177,493				174,940	177,493
Loans collectively evaluated for impairment, balance	20,704,670				18,556,914				20,704,670	18,556,914
Non-covered loans, net of premiums, discounts and deferred fees and costs	20,913,386				18,781,352				20,913,386	18,781,352
Non-Covered [Domain] | Residential and Other Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									1,034	(1,814)	3,988
Charge-offs									(1)	(152)	0
Recoveries									26	26	32
Financing Receivable, Allowance for Credit Losses	10,462				9,403				10,462	9,403
Allowance, balance, loans individually evaluated for impairment	63				12				63	12
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	10,399				9,391				10,399	9,391
Loans individually evaluated for impairment, balance	1,234				561				1,234	561
Loans collectively evaluated for impairment, balance	4,194,846				3,495,207				4,194,846	3,495,207
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,196,080				3,495,775				4,196,080	3,495,775
Non-Covered [Domain] | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Provision for (recovery of) loan losses									66,355	54,406	38,072
Charge-offs									(77,865)	(25,742)	(13,719)
Recoveries									4,135	3,169	$ 1,237
Financing Receivable, Allowance for Credit Losses	134,075				141,450				134,075	141,450
Allowance, balance, loans individually evaluated for impairment	18,776				19,229				18,776	19,229
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	115,299				122,221				115,299	122,221
Loans individually evaluated for impairment, balance	173,706				176,932				173,706	176,932
Loans collectively evaluated for impairment, balance	16,509,824				15,061,707				16,509,824	15,061,707
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 16,717,306				$ 15,285,577				$ 16,717,306	$ 15,285,577

Loans and Allowance for Loan 65

Loans and Allowance for Loan and Lease Losses (Impaired Financing Receivables) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Impaired [Line Items]
Recorded Investment, Total	$ 174,940	$ 178,828
UPB, Total	174,865	178,707
Related Specific Allowance, Impaired loans	18,839	19,241
Multi-family
Financing Receivable Impaired [Line Items]
Recorded Investment, With a specific allowance recorded	23,173	0
UPB, With a specific allowance recorded	23,175	0
Related Specific Allowance, Impaired loans	1,732	0
Commercial real estate, Non-owner occupied
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	10,922	510
UPB, With no specific allowance recorded	10,838	512
Construction and land
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	1,175	1,238
UPB, With no specific allowance recorded	1,175	1,238
Commercial real estate, Owner occupied
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	22,002	16,834
Recorded Investment, With a specific allowance recorded	3,075	491
UPB, With no specific allowance recorded	22,025	16,894
UPB, With a specific allowance recorded	3,079	513
Related Specific Allowance, Impaired loans	2,960	263
Taxi medallion [Member]
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	13,560	18,107
Recorded Investment, With a specific allowance recorded	92,507	73,131
UPB, With no specific allowance recorded	13,559	18,107
UPB, With a specific allowance recorded	92,508	73,147
Related Specific Allowance, Impaired loans	12,214	5,948
Other Commercial and industrial [Member]
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	345	6,172
Recorded Investment, With a specific allowance recorded	3,626	29,452
UPB, With no specific allowance recorded	374	6,172
UPB, With a specific allowance recorded	3,624	29,463
Related Specific Allowance, Impaired loans	1,540	9,168
Commercial Lending Subsidiaries
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	0	10,620
Recorded Investment, With a specific allowance recorded	3,321	21,712
UPB, With no specific allowance recorded	0	10,510
UPB, With a specific allowance recorded	3,296	21,605
Related Specific Allowance, Impaired loans	330	3,850
Residential and Other Consumer
Financing Receivable Impaired [Line Items]
Recorded Investment, Total	1,234	561
UPB, Total	1,212	546
Related Specific Allowance, Impaired loans	63	12
Commercial
Financing Receivable Impaired [Line Items]
Recorded Investment, Total	173,706	178,267
UPB, Total	173,653	178,161
Related Specific Allowance, Impaired loans	18,776	19,229
Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	120	0
Recorded Investment, With a specific allowance recorded	1,114	561
UPB, With no specific allowance recorded	122	0
UPB, With a specific allowance recorded	1,090	546
Related Specific Allowance, Impaired loans	63	12
Non-ACI loans [Member]
Financing Receivable Impaired [Line Items]
Recorded Investment, Total	2,221	12,396
UPB, Total	2,517	12,995
Related Specific Allowance, Impaired loans	118	529
Non-ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	1,061	1,169
Recorded Investment, With a specific allowance recorded	1,160	1,272
UPB, With no specific allowance recorded	1,203	1,391
UPB, With a specific allowance recorded	1,314	1,514
Related Specific Allowance, Impaired loans	118	181
Non-ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	0	2,255
Recorded Investment, With a specific allowance recorded	0	7,700
UPB, With no specific allowance recorded	0	2,286
UPB, With a specific allowance recorded	0	7,804
Related Specific Allowance, Impaired loans	0	348
Non-ACI Loans, Covered [Member] | Residential and Other Consumer
Financing Receivable Impaired [Line Items]
Recorded Investment, Total	2,221	12,396
UPB, Total	2,517	12,995
Related Specific Allowance, Impaired loans	118	529
ACI loans
Financing Receivable Impaired [Line Items]
Recorded Investment, With a specific allowance recorded	0	0
UPB, With a specific allowance recorded	0	0
Related Specific Allowance, Impaired loans	0	0
ACI loans | Commercial real estate, Owner occupied
Financing Receivable Impaired [Line Items]
Recorded Investment, With no specific allowance recorded	$ 0	$ 1,300

Loans and Allowance for Loan 66

Loans and Allowance for Loan and Lease Losses Loans and Allowance for Loan and Lease Losses (Schedule of Average Recorded Investment in Impaired Loans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	$ 203,452	$ 116,960
Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans			$ 57,302
1-4 single family residential | Non-ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	2,345	3,067	3,655
1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	868	301	82
Home equity loans and lines of credit | Non-ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	8,403	9,225	4,830
Home equity loans and lines of credit | ACI loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	3,900
Home equity loans and lines of credit | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	0	0
Residential and Other Consumer | Non-ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	10,748	12,292	8,485
Residential and Other Consumer | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	868	301	82
Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	4,259	0
Multi-family | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans			291
Commercial real estate, Non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	5,537	710
Commercial real estate, Non-owner occupied | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans			1,001
Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	2,789	797
Construction and land | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans			0
Commercial real estate, Owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	19,882	14,645	5,117
Taxi medallion [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	108,977	45,012	0
Other Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	38,275	40,443	35,976
Commercial Lending Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	22,865	15,052
Commercial Lending Subsidiaries | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans			14,835
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans	$ 202,584	$ 116,659
Commercial | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average recorded investment in impaired loans			$ 57,220

Loans and Allowance for Loan 67

Loans and Allowance for Loan and Lease Losses (Schedule of Recorded Investment in Loans, Other than ACI Loans, on Non-Accrual Status) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 170,065	$ 131,145
1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	9,705	566
1-4 single family residential | Non-ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,010	918
Home equity loans and lines of credit | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Home equity loans and lines of credit | Non-ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	331	2,283
Other Consumer Loans | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	821	2
Residential and Other Consumer | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	10,526	568
Residential and Other Consumer | Non-ACI Loans, Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,341	3,201
Commercial real estate, Non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	12,716	559
Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,175	1,238
Commercial real estate, Owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	29,020	19,439
Taxi medallion [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	106,067	60,660
Other Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	7,049	16,036
Commercial Lending Subsidiaries
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	3,512	32,645
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 159,539	$ 130,577

Loans and Allowance for Loan 68

Loans and Allowance for Loan and Lease Losses (Schedule of Credit Exposure for Non-Covered Loans Based on Original LTV and FICO Score) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 20,913,386	$ 18,781,352
Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,173,953	3,470,349
Non-Covered [Domain] | FICO, 720 or less | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	377,208	300,353
Non-Covered [Domain] | FICO, 721 to 740 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	436,764	365,262
Non-Covered [Domain] | FICO, 741 to 760 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	688,076	579,743
Non-Covered [Domain] | FICO, 761 or greater | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,671,905	2,224,991
60% or less | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,210,656	1,115,395
60% or less | Non-Covered [Domain] | FICO, 720 or less | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	92,316	87,035
60% or less | Non-Covered [Domain] | FICO, 721 to 740 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	117,319	113,401
60% or less | Non-Covered [Domain] | FICO, 741 to 760 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	185,193	163,668
60% or less | Non-Covered [Domain] | FICO, 761 or greater | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	815,828	751,291
60% - 70% | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	942,949	823,436
60% - 70% | Non-Covered [Domain] | FICO, 720 or less | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	101,158	80,694
60% - 70% | Non-Covered [Domain] | FICO, 721 to 740 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	103,506	94,592
60% - 70% | Non-Covered [Domain] | FICO, 741 to 760 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	147,592	124,180
60% - 70% | Non-Covered [Domain] | FICO, 761 or greater | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	590,693	523,970
70% - 80% | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,798,190	1,442,595
70% - 80% | Non-Covered [Domain] | FICO, 720 or less | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	149,958	110,509
70% - 80% | Non-Covered [Domain] | FICO, 721 to 740 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	183,376	148,211
70% - 80% | Non-Covered [Domain] | FICO, 741 to 760 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	324,887	276,425
70% - 80% | Non-Covered [Domain] | FICO, 761 or greater | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,139,969	907,450
More than 80% | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	222,158	88,923
More than 80% | Non-Covered [Domain] | FICO, 720 or less | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	33,776	22,115
More than 80% | Non-Covered [Domain] | FICO, 721 to 740 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	32,563	9,058
More than 80% | Non-Covered [Domain] | FICO, 741 to 760 | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	30,404	15,470
More than 80% | Non-Covered [Domain] | FICO, 761 or greater | 1-4 single family residential
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 125,415	$ 42,280

Loans and Allowance for Loan 69

Loans and Allowance for Loan and Lease Losses (Schedule of Commercial Credit Exposure Based on Internal Risk Ratings) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 20,913,386	$ 18,781,352
Multi-family
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	3,218,953	3,829,674
Multi-family | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	3,124,819	3,811,822
Multi-family | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	34,837	12,000
Multi-family | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	59,297	5,852
Multi-family | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	0
Commercial real estate, Non-owner occupied
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,474,801	3,731,808
Commercial real estate, Non-owner occupied | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,360,827	3,694,931
Commercial real estate, Non-owner occupied | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	33,094	7,942
Commercial real estate, Non-owner occupied | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	80,880	28,935
Commercial real estate, Non-owner occupied | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	0
Construction and land
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	310,484	310,913
Construction and land | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	305,043	309,675
Construction and land | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	0
Construction and land | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	5,441	1,238
Construction and land | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	0
Commercial real estate, Owner occupied
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,012,742	1,735,850
Commercial real estate, Owner occupied | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,954,464	1,672,199
Commercial real estate, Owner occupied | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	22,161	33,274
Commercial real estate, Owner occupied | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	33,145	30,377
Commercial real estate, Owner occupied | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,972	0
Taxi medallion [Member]
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	106,067	178,673
Taxi medallion [Member] | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	40,460
Taxi medallion [Member] | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	0
Taxi medallion [Member] | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	104,682	138,035
Taxi medallion [Member] | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,385	178
Other Commercial and industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,031,760	3,208,465
Other Commercial and industrial [Member] | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	3,965,241	3,112,590
Other Commercial and industrial [Member] | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	37,591	19,009
Other Commercial and industrial [Member] | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	27,010	68,704
Other Commercial and industrial [Member] | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,918	8,162
Commercial Lending Subsidiaries
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,562,499	2,290,194
Commercial Lending Subsidiaries | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,478,998	2,255,444
Commercial Lending Subsidiaries | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	55,551	0
Commercial Lending Subsidiaries | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	27,950	31,572
Commercial Lending Subsidiaries | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	0	3,178
Commercial
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	16,717,306	15,285,577
Commercial | Pass
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	16,189,392	14,897,121
Commercial | Special mention
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	183,234	72,225
Commercial | Substandard
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	338,405	304,713
Commercial | Doubtful
Financing Receivable Recorded Investment [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 6,275	$ 11,518

Loans and Allowance for Loan 70

Loans and Allowance for Loan and Lease Losses (Schedule of Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Investment Past Due [Line Items]
Loans, Current	$ 20,840,121	$ 18,699,976
Covered loans net of premiums, discounts and deferred fees and costs	503,118	614,042
Non-covered loans, net of premiums, discounts and deferred fees and costs	20,913,386	18,781,352
Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Loans, Current	19,958	24,306
Non-covered loans, net of premiums, discounts and deferred fees and costs	20,473	24,306
Multi-family
Financing Receivable Investment Past Due [Line Items]
Loans, Current	3,218,953	3,829,674
Non-covered loans, net of premiums, discounts and deferred fees and costs	3,218,953	3,829,674
Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Loans, Current	4,464,967	3,730,470
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,474,801	3,731,808
Construction and land
Financing Receivable Investment Past Due [Line Items]
Loans, Current	309,309	309,675
Non-covered loans, net of premiums, discounts and deferred fees and costs	310,484	310,913
Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Loans, Current	2,004,397	1,726,826
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,012,742	1,735,850
Taxi medallion [Member]
Financing Receivable Investment Past Due [Line Items]
Loans, Current	88,394	137,856
Non-covered loans, net of premiums, discounts and deferred fees and costs	106,067	178,673
Other Commercial and industrial [Member]
Financing Receivable Investment Past Due [Line Items]
Loans, Current	4,025,784	3,198,008
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,031,760	3,208,465
Commercial Lending Subsidiaries
Financing Receivable Investment Past Due [Line Items]
Loans, Current	2,561,647	2,284,435
Non-covered loans, net of premiums, discounts and deferred fees and costs	2,562,499	2,290,194
Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans, Current	4,145,079	3,457,606
Non-covered loans, net of premiums, discounts and deferred fees and costs	4,173,953	3,470,349
Non-Covered [Domain] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Loans, Current	1,633	1,120
Non-covered loans, net of premiums, discounts and deferred fees and costs	1,654	1,120
Non-ACI Loans, Covered [Member]
Financing Receivable Investment Past Due [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	24,050	77,800
Non-ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans, Current	21,076	29,406
Covered loans net of premiums, discounts and deferred fees and costs	23,689	30,805
Non-ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Loans, Current	30	43,129
Covered loans net of premiums, discounts and deferred fees and costs	361	46,995
Non-ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Loans, Current	21,106	72,535
Covered loans net of premiums, discounts and deferred fees and costs	24,050	77,800
ACI Loans, Covered [Member]
Financing Receivable Investment Past Due [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	479,068	536,242
ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Loans, Current	448,125	500,272
Covered loans net of premiums, discounts and deferred fees and costs	479,068	532,348
ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Loans, Current	0	3,460
Covered loans net of premiums, discounts and deferred fees and costs	0	3,894
ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Loans, Current	448,125	503,732
Covered loans net of premiums, discounts and deferred fees and costs	479,068	536,242
30 - 59 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	37,292	22,230
30 - 59 Days Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	15	0
30 - 59 Days Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
30 - 59 Days Past Due | Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	7,549	754
30 - 59 Days Past Due | Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
30 - 59 Days Past Due | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,292	1,557
30 - 59 Days Past Due | Taxi medallion [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	6,048	7,037
30 - 59 Days Past Due | Other Commercial and industrial [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,291	2,515
30 - 59 Days Past Due | Commercial Lending Subsidiaries
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	852	12
30 - 59 Days Past Due | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	17,224	10,355
30 - 59 Days Past Due | Non-Covered [Domain] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	21	0
30 - 59 Days Past Due | Non-ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,603	481
30 - 59 Days Past Due | Non-ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	1,255
30 - 59 Days Past Due | Non-ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,603	1,736
30 - 59 Days Past Due | ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	10,388	13,524
30 - 59 Days Past Due | ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	148
30 - 59 Days Past Due | ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	10,388	13,672
60 - 89 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	10,217	9,886
60 - 89 Days Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
60 - 89 Days Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
60 - 89 Days Past Due | Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
60 - 89 Days Past Due | Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
60 - 89 Days Past Due | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	499	797
60 - 89 Days Past Due | Taxi medallion [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,333	4,563
60 - 89 Days Past Due | Other Commercial and industrial [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	291	954
60 - 89 Days Past Due | Commercial Lending Subsidiaries
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	3,247
60 - 89 Days Past Due | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	6,094	325
60 - 89 Days Past Due | Non-Covered [Domain] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
60 - 89 Days Past Due | Non-ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
60 - 89 Days Past Due | Non-ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	534
60 - 89 Days Past Due | Non-ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	534
60 - 89 Days Past Due | ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,719	2,990
60 - 89 Days Past Due | ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	23
60 - 89 Days Past Due | ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,719	3,013
90 Days or More Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	25,756	49,260
90 Days or More Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	500	0
90 Days or More Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
90 Days or More Past Due | Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	2,285	584
90 Days or More Past Due | Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,175	1,238
90 Days or More Past Due | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	6,554	6,670
90 Days or More Past Due | Taxi medallion [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	8,292	29,217
90 Days or More Past Due | Other Commercial and industrial [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,394	6,988
90 Days or More Past Due | Commercial Lending Subsidiaries
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	2,500
90 Days or More Past Due | Non-Covered [Domain] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	5,556	2,063
90 Days or More Past Due | Non-Covered [Domain] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
90 Days or More Past Due | Non-ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,010	918
90 Days or More Past Due | Non-ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	331	2,077
90 Days or More Past Due | Non-ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,341	2,995
90 Days or More Past Due | ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	17,836	15,562
90 Days or More Past Due | ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	263
90 Days or More Past Due | ACI Loans, Covered [Member] | Residential Mortgage [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 17,836	$ 15,825

Loans and Allowance for Loan 71

Loans and Allowance for Loan and Lease Losses Loans and Allowance for Loan and Lease Losses (Schedule of Loan Concentrations by States) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 20,913,386	$ 18,781,352
Covered loans net of premiums, discounts and deferred fees and costs	503,118	614,042
Loans net of premiums, discounts and deferred fees and costs	21,416,504	19,395,394
1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans net of premiums, discounts and deferred fees and costs	$ 4,676,710	$ 4,033,502
Percent of loans by state	100.00%	100.00%
1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 4,173,953	$ 3,470,349
Percent of loans by state	100.00%	100.00%
1-4 single family residential | Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	$ 502,757	$ 563,153
California [Member] | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans net of premiums, discounts and deferred fees and costs	$ 1,117,838	$ 941,437
Percent of loans by state	23.90%	23.30%
California [Member] | 1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 1,094,058	$ 904,107
Percent of loans by state	26.20%	26.10%
California [Member] | 1-4 single family residential | Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	$ 23,780	$ 37,330
New York [Member] | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans net of premiums, discounts and deferred fees and costs	$ 890,207	$ 780,227
Percent of loans by state	19.00%	19.30%
New York [Member] | 1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 873,360	$ 763,824
Percent of loans by state	20.90%	22.00%
New York [Member] | 1-4 single family residential | Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	$ 16,847	$ 16,403
Virginia [Member] | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans net of premiums, discounts and deferred fees and costs	$ 204,202	$ 182,931
Percent of loans by state	4.40%	4.50%
Virginia [Member] | 1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 181,912	$ 152,113
Percent of loans by state	4.40%	4.40%
Virginia [Member] | 1-4 single family residential | Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	$ 22,290	$ 30,818
Florida [Member] | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans net of premiums, discounts and deferred fees and costs	$ 833,952	$ 787,492
Percent of loans by state	17.80%	19.50%
Florida [Member] | 1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 552,556	$ 487,294
Percent of loans by state	13.20%	14.00%
Florida [Member] | 1-4 single family residential | Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	$ 281,396	$ 300,198
Others [Member] | 1-4 single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans net of premiums, discounts and deferred fees and costs	$ 1,630,511	$ 1,341,415
Percent of loans by state	34.90%	33.40%
Others [Member] | 1-4 single family residential | Non-Covered [Domain]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-covered loans, net of premiums, discounts and deferred fees and costs	$ 1,472,067	$ 1,163,011
Percent of loans by state	35.30%	33.50%
Others [Member] | 1-4 single family residential | Covered [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Covered loans net of premiums, discounts and deferred fees and costs	$ 158,444	$ 178,404

Loans and Allowance for Loan 72

Loans and Allowance for Loan and Lease Losses Loans and Allowance for Loan and Lease Losses (Schedule of Troubled Debt Restructurings) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Non-Covered [Domain]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	124	93	3
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 78,438	$ 100,279	$ 1,808
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	13	19	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 3,320	$ 13,130	$ 627
Non-Covered [Domain] | 1-4 single family residential
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	7	2
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 676	$ 326
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	5	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 595	$ 0
Non-Covered [Domain] | Multi-family
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	2
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 23,173
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0
Non-Covered [Domain] | Commercial real estate, Non-owner occupied
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts			1
Financing Receivable, Modifications, Post-Modification Recorded Investment			$ 548
Financing Receivable, Modifications, Subsequent Default, Number of Contracts			0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment			$ 0
Non-Covered [Domain] | Commercial real estate, Owner occupied
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	3	3
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 4,685	$ 5,117
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 491
Non-Covered [Domain] | Taxi medallion [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	110	74	2
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 48,526	$ 64,854	$ 1,260
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	8	15	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 2,725	$ 8,657	$ 627
Non-Covered [Domain] | Other Commercial and industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	2	8
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 1,378	$ 23,247
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 1,482
Non-Covered [Domain] | Commercial Lending Subsidiaries
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts		6
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 6,735
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 2,500
Non-ACI Loans, Covered [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts			30
Financing Receivable, Modifications, Post-Modification Recorded Investment			$ 6,447
Financing Receivable, Modifications, Subsequent Default, Number of Contracts			7
Financing Receivable, Modifications, Subsequent Default, Recorded Investment			$ 1,231
Non-ACI Loans, Covered [Member] | 1-4 single family residential
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts			2
Financing Receivable, Modifications, Post-Modification Recorded Investment			$ 239
Financing Receivable, Modifications, Subsequent Default, Number of Contracts			0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment			$ 0
Non-ACI Loans, Covered [Member] | Home equity loans and lines of credit
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts		17	28
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 2,016	$ 6,208
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		1	7
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 370	$ 1,231
ACI Loans, Covered [Member] | Commercial real estate, Owner occupied
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts		1	1
Financing Receivable, Modifications, Post-Modification Recorded Investment		$ 825	$ 500
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 0	$ 0

FDIC Indemnification Asset (Gai

FDIC Indemnification Asset (Gains and Losses Associated with Covered Assets) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Guarantor Obligations [Line Items]
Provision for losses on covered loans	$ (5,174)	$ (37,854)	$ (13,619)	$ (12,100)	$ (8,462)	$ (24,408)	$ (14,333)	$ (3,708)	$ (68,747)	$ (50,911)	$ (44,311)
Income from resolution of covered assets, net									27,450	36,155	50,658
Gain (Loss) on Sale of Covered Loans									27,589	(4,406)	40,633
Covered [Member]
Guarantor Obligations [Line Items]
Provision for losses on covered loans									(1,358)	1,681	(2,251)
Income from resolution of covered assets, net									27,450	36,155	50,658
Gain (Loss) on Sale of Covered Loans									17,406	(14,470)	34,929
Gains (Losses) on Sales of Covered OREO									(203)	(1,301)	(1,014)
Gain (Loss) Associated With Covered Assets									43,295	22,065	82,322
Covered [Member] | Net Loss on FDIC Indemnification
Guarantor Obligations [Line Items]
Provision for losses on covered loans									1,039	(1,472)	1,826
Income from resolution of covered assets, net									(21,912)	(28,946)	(40,395)
Gain (Loss) on Sale of Covered Loans									(1,514)	11,615	(28,051)
Gains (Losses) on Sales of Covered OREO									167	1,044	678
Gain (Loss) Associated With Covered Assets									(22,220)	(17,759)	(65,942)
Covered [Member] | Net Impact on Pre-tax Earnings
Guarantor Obligations [Line Items]
Provision for losses on covered loans									(319)	209	(425)
Income from resolution of covered assets, net									5,538	7,209	10,263
Gain (Loss) on Sale of Covered Loans									15,892	(2,855)	6,878
Gains (Losses) on Sales of Covered OREO									(36)	(257)	(336)
Gain (Loss) Associated With Covered Assets									$ 21,075	$ 4,306	$ 16,380

FDIC Indemnification Asset (Cha

FDIC Indemnification Asset (Changes in the FDIC Indemnification Asset) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
FDIC Indemnification Asset [Roll Forward]
FDIC Indemnification Asset and Liability, net	$ 515,910	$ 739,843	$ 974,335
Amortization of FDIC indemnification asset	(176,466)	(160,091)	(109,411)
FDIC Indemnification Asset, Cash Payments Received	(21,589)	(46,083)	(59,139)
Net gain (loss) on FDIC indemnification	(22,220)	(17,759)	(65,942)
FDIC Indemnification Asset and Liability, net	$ 295,635	$ 515,910	$ 739,843

FDIC Indemnification Asset (Bal

FDIC Indemnification Asset (Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
FDIC Indemnification Asset [Abstract]
FDIC indemnification asset	$ 295,635	$ 515,933
Other Liabilities	0	(23)
FDIC Indemnification Asset and Liability, net	$ 295,635	$ 515,910	$ 739,843	$ 974,335

Equipment Under Operating Lea76

Equipment Under Operating Lease (Schedule of Equipment Under Operating Lease) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Property Subject to or Available for Operating Lease, Gross	$ 674,434	$ 589,716
Property Subject to or Available for Operating Lease, Accumulated Depreciation	(74,932)	(49,802)
Property Subject to or Available for Operating Lease, Net	599,502	539,914
Impairment of equipment under operating lease	$ 0	$ 4,100	$ 0

Equipment Under Operating Lea77

Equipment Under Operating Lease (Schedule of Future Minimum Rental Payments) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Years Ending December 31:
Operating Leases, Future Minimum Payments Receivable, Current	$ 50,173
Operating Leases, Future Minimum Payments Receivable, in Two Years	46,547
Operating Leases, Future Minimum Payments Receivable, in Three Years	40,956
Operating Leases, Future Minimum Payments Receivable, in Four Years	31,425
Operating Leases, Future Minimum Payments Receivable, in Five Years	25,185
Operating Leases, Future Minimum Payments, Due Thereafter	58,304
Operating Leases, Future Minimum Payments Receivable	$ 252,590

Premises and Equipment and Le78

Premises and Equipment and Lease Commitments (Summary of Premises and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 200,496	$ 195,385
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(121,477)	(104,268)
Property, Plant and Equipment, Net	79,019	91,117
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	18,793	22,470
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	70,298	68,403
Furniture, Fixtures And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	35,675	36,094
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	21,078	18,559
Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	42,908	38,002
Transportation Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 11,744	$ 11,857

Premises and Equipment and Le79

Premises and Equipment and Lease Commitments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment, Type [Abstract]
Amount included buildings and improvements recorded under capital lease	$ 11	$ 11
Depreciation, Nonproduction	19.4	21.3	$ 22.9
Operating Leases, Rent Expense, Net	$ 27.5	$ 27.6	$ 27.1

Premises and Equipment and Le80

Premises and Equipment and Lease Commitments (Schedule of Future Minimum Rentals Under Non-Cancelable Operating Leases) (Details) - Land and Building [Member] $ in Thousands	Dec. 31, 2017USD ($)
Operating Leased Assets [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 22,340
Operating Leases, Future Minimum Payments, Due in Two Years	21,129
Operating Leases, Future Minimum Payments, Due in Three Years	17,541
Operating Leases, Future Minimum Payments, Due in Four Years	15,770
Operating Leases, Future Minimum Payments, Due in Five Years	11,712
Operating Leases, Future Minimum Payments, Due Thereafter	48,183
Operating Leases, Future Minimum Payments Due	$ 136,675

Deposits (Summary of Average Ba

Deposits (Summary of Average Balances and Weighted Average Rates Paid on Deposits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Demand deposits:
Non-interest bearing, average balance	$ 3,069,565	$ 2,968,192	$ 2,732,654
Non-interest bearing, average rate (in Percent)	0.00%	0.00%	0.00%
Interest bearing, average balance	$ 1,586,390	$ 1,382,717	$ 1,169,921
Interest-bearing, average rate (in Percent)	0.81%	0.60%	0.49%
Money market, average balance	$ 9,364,498	$ 7,946,447	$ 6,313,340
Weighted Average Rate Domestic Deposit, Money Market	0.85%	0.64%	0.57%
Savings, average balance	$ 365,603	$ 415,205	$ 536,026
Weighted Average Rate Domestic Deposit, Savings	0.21%	0.23%	0.32%
Time, average balance	$ 6,094,336	$ 5,326,630	$ 4,305,857
Weighted Average Rate Domestic Deposit, Time Deposits	1.27%	1.12%	1.11%
Total, average balance	$ 20,480,392	$ 18,039,191	$ 15,057,798
Weighted Average Rate, Interest-bearing Domestic Deposits, Point in Time	0.83%	0.66%	0.61%

Deposits (Narrative) (Details)

Deposits (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Time Deposits, $100,000 or More	$ 4.1	$ 3.9
Time deposit accounts with balances of $250,000 or more	2.3	$ 2.1
Public funds deposits included in deposits	2.6
Interest-bearing Domestic Deposit, Brokered	2.4
Carrying value of investment securities available for sale pledged as security for public funds deposits	$ 1.2

Deposits (Schedule of Maturitie

Deposits (Schedule of Maturities of Time Deposits) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Time Deposit Maturities, Next Twelve Months	$ 5,228,690
Time Deposit Maturities, Year Two	630,719
Time Deposit Maturities, Year Three	345,861
Time Deposit Maturities, Year Four	101,715
Time Deposit Maturities, Year Five	27,809
Time Deposit Maturities, after Year Five	48
Time Deposits	$ 6,334,842	$ 5,755,642

Deposits (Schedule of Interest

Deposits (Schedule of Interest Expense on Deposits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Interest Expense, Demand Deposit Accounts	$ 12,873	$ 8,343	$ 5,782
Interest Expense, Money Market Deposits	79,645	50,802	36,005
Interest Expense, Savings Deposits	752	972	1,739
Interest Expense, Time Deposits	77,663	59,656	47,625
Interest Expense, Domestic Deposits	$ 170,933	$ 119,773	$ 91,151

Federal Home Loan Bank Advanc85

Federal Home Loan Bank Advances and Other Borrowings (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Percent of outstanding FHLB Advances of which the sum of qualifying first mortgages, CRE loans, Home equity lines and credit and mortgage-backed securities pledged must equal (in Percent)	100.00%
Pledged Financial Instruments, Not Separately Reported, Securities for Federal Home Loan Bank	$ 10,700
Debt Instrument, Interest Rate, Effective Percentage	5.12%
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds	$ 4,100
Federal Reserve Bank Advances [Member]
Debt Instrument [Line Items]
Unused borrowing capacity at FRB	770
Federal Funds Lines of Credit [Member]
Debt Instrument [Line Items]
Unused Borrowing Capacity - Fed Funds lines of credit	$ 70

Federal Home Loan Bank Advanc86

Federal Home Loan Bank Advances and Other Borrowings (Schedule of Outstanding FHLB Advances) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maturing in Next Twelve Months - One month or less	$ 2,425,000
Maturing in Next Twelve Months - One month or less, Weighted Average Rate (in Percent)	1.35%
Maturing in Next Twelve Months - Over one month	$ 2,121,000
Maturing in Next Twelve Months - Over one month, Weighted Average Rate (in Percent)	1.43%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Two	$ 100,000
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, One to Two Years from Balance Sheet Date	1.52%
Federal Home Loan Bank, Advances, Maturities Summary, Due in Year Three	$ 125,000
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate, Two to Three Years from Balance Sheet Date	1.73%
Advances from Federal Home Loan Banks	$ 4,771,000	$ 5,239,348
Minimum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maturing in Next Twelve Months - One month or less, range of interest rates (in Percent)	1.20%
Maturing in Next Twelve Months - Over one month, range of interest rates (in Percent)	1.25%
Maturing in Year Two, range of interest rates (in Percent)	1.46%
Maturing in Year Three, range of interest rates (in Percent)	1.67%
Maximum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maturing in Next Twelve Months - One month or less, range of interest rates (in Percent)	1.42%
Maturing in Next Twelve Months - Over one month, range of interest rates (in Percent)	1.69%
Maturing in Year Two, range of interest rates (in Percent)	1.57%
Maturing in Year Three, range of interest rates (in Percent)	1.78%

Federal Home Loan Bank Advanc87

Federal Home Loan Bank Advances, Notes and Other Borrowings Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Long-term Debt, Gross	$ 400,000	$ 400,000
Debt Instrument, Unamortized Discount	6,275	6,908
Long-term Debt	393,725	393,092
Capital Lease Obligations	9,105	9,717
Long-term Debt and Capital Lease Obligations	$ 402,830	$ 402,809

Income Taxes (Schedule of Compo

Income Taxes (Schedule of Components of the Provision for Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)									$ (251,880)	$ 51,806	$ 18,230
Current State and Local Tax Expense (Benefit)									(15,733)	27,708	(2,468)
Current Income Tax Expense (Benefit)									(267,613)	79,514	15,762
Deferred Federal Income Tax Expense (Benefit)									46,377	35,045	20,509
Deferred State and Local Income Tax Expense (Benefit)									11,424	(4,856)	8,962
Deferred Income Tax Expense (Benefit)									57,801	30,189	29,471
Income Tax Expense (Benefit)	$ (298,872)	$ 32,252	$ 29,021	$ 27,787	$ 28,807	$ 23,550	$ 27,997	$ 29,349	$ (209,812)	$ 109,703	$ 45,233

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Impact of change in enacted tax rate on income tax expense	$ 3.7
Deferred State and Local Income Tax Expense (Benefit), Tax Law Changes			$ (2)
Amortization Method Qualified Affordable Housing Project Investments	64	$ 71
Qualified Affordable Housing Project Investments, Commitment	26	53
Maximum Loss Exposure Amount, Affordable Housing VIEs	72
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	43.6	45	27
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	3.2	2.5
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, net of tax	0.3	$ 1.1	$ (1.8)
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Discrete Income Tax Benefit - Estimated Income Tax Refund	295
Discrete Income Tax Benefit	8.7
Operating Loss Carryforwards	10
State and Local Jurisdiction [Member]
Tax Credit Carryforward [Line Items]
Discrete Income Tax Benefit - Estimated Income Tax Refund	24.2
Operating Loss Carryforwards	100.4
Tax Credit Carryforward, Amount	9.4
State and Local Jurisdiction [Member] | Minimum
Tax Credit Carryforward [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	0
State and Local Jurisdiction [Member] | Maximum [Member]
Tax Credit Carryforward [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 41.2

Income Taxes (Schedule of Effec

Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount									$ 141,561	$ 117,405	$ 103,912
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent									35.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount									$ (29,511)	$ (23,215)	$ (14,279)
Effective Income Tax Rate Reconciliation, Tax Exempt Income, Percent									(7.30%)	(6.92%)	(4.81%)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount									$ 19,332	$ 15,894	$ 12,889
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent									4.78%	4.74%	4.34%
Uncertain state tax positions, lapse of statute amount									$ (2,696)	$ 0	$ (6,166)
Effective Income Tax Rate Reconciliation Uncertain Tax Positions Reversal									(0.66%)	0.00%	(2.08%)
Discrete Income Tax Benefit									$ (327,945)	$ 0	$ (49,323)
Effective Income Tax Rate Reconciliation, Discrete Tax Benefit									(81.08%)	0.00%	(16.61%)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount									$ (10,553)	$ (381)	$ (1,800)
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent									(2.61%)	(0.12%)	(0.60%)
Income Tax Expense (Benefit)	$ (298,872)	$ 32,252	$ 29,021	$ 27,787	$ 28,807	$ 23,550	$ 27,997	$ 29,349	$ (209,812)	$ 109,703	$ 45,233
Effective Income Tax Rate Reconciliation, Percent									(51.87%)	32.70%	15.24%

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Excess of tax basis over carrying value of acquired loans	$ 66,395	$ 130,004
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	33,309	52,670
Deferred Tax Assets, Operating Loss Carryforwards	15,892	11,641
Deferred Tax Assets, Other	31,859	51,911
Deferred Tax Assets, Gross	147,455	246,226
Deferred tax liabilities:
Net unrealized gains on investment securities available for sale	24,657	30,566
Deferred Tax Liabilities, Leasing Arrangements	113,161	145,700
Deferred Tax Liabilities, Other	13,468	7,020
Deferred Tax Liabilities, Gross	151,286	183,286
Deferred Tax Liabilities, Net	$ (3,831)
Deferred Tax Assets, Net		$ 62,940

Income Taxes (Schedule of Unrec

Income Taxes (Schedule of Unrecognized Tax Benefits, Roll Forward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits	$ 59,220	$ 72,736	$ 43,412	$ 36,622
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	1,882	2,713	2,909
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	1,661	25,168	11,618
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	(15,316)	0	0
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	0	(200)	(246)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	(2,229)	0	(5,438)
Unrecognized Tax Benefits, Period Increase (Decrease)	58,734	71,093	45,465
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	$ 486	$ 1,643	$ (2,053)

Derivatives and Hedging Activ93

Derivatives and Hedging Activities (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of Interest rate derivative contracts cleared through the CME	$ 0
Discontinuation of Cash Flow Hedge	0	$ 0	$ 0
Gains and losses reported in AOCI that were reclassified into earnings as a result of discontinuance of cash flow hedges or early extinguishment of debt	0	$ 0	$ 0
Amount expected to be reclassified from AOCI into income	1,200,000
Available for Sale Securities Pledged as Collateral for Interest Rate Swaps	31,000,000
Financial collateral pledged by counterparties to Company	$ (7,000,000)

Derivatives and Hedging Activ94

Derivatives and Hedging Activities (Interest Rate Contract Derivative Financial Instruments and Related Hedged Items) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Notional amount of interest rate derivatives	$ 4,392,790	$ 4,217,114
Interest rate derivative assets, fair value	27,627	50,232
Interest rate derivative liabilities, fair value	$ (25,373)	$ (61,562)
Derivatives designated as cash flow hedges | Pay-fixed interest rate swaps
Derivatives Fair Value [Line Items]
Weighted average fixed rate of interest rate derivatives (in Percent)	1.77%	1.58%
Weighted average remaining maturity of interest rate derivatives (in Duration)	4 years 3 months 23 days	3 years 4 months 4 days
Notional amount of interest rate derivatives	$ 2,046,000	$ 1,715,000
Derivatives designated as cash flow hedges | Pay-fixed interest rate swaps | Other Liabilities
Derivatives Fair Value [Line Items]
Interest rate derivative liabilities, fair value	0	(3,112)
Derivatives designated as cash flow hedges | Pay-fixed interest rate swaps | Other Assets
Derivatives Fair Value [Line Items]
Interest rate derivative assets, fair value	$ 2,350	$ 19,648
Derivatives designated as cash flow hedges | Pay-Fixed Forward-Starting Swap - Borrowings
Derivatives Fair Value [Line Items]
Weighted average fixed rate of interest rate derivatives (in Percent)		3.43%
Weighted average remaining maturity of interest rate derivatives (in Duration)		10 years 5 months 15 days
Notional amount of interest rate derivatives		$ 300,000
Derivatives designated as cash flow hedges | Pay-Fixed Forward-Starting Swap - Borrowings | Other Liabilities
Derivatives Fair Value [Line Items]
Interest rate derivative liabilities, fair value		(27,866)
Derivatives designated as cash flow hedges | Pay-Fixed Forward-Starting Swap - Borrowings | Other Assets
Derivatives Fair Value [Line Items]
Interest rate derivative assets, fair value		$ 0
Derivatives not designated as hedges | Pay-fixed interest rate swaps
Derivatives Fair Value [Line Items]
Weighted average fixed rate of interest rate derivatives (in Percent)	3.87%	3.77%
Weighted average remaining maturity of interest rate derivatives (in Duration)	6 years 4 months 19 days	6 years 9 months
Notional amount of interest rate derivatives	$ 1,028,041	$ 912,000
Derivatives not designated as hedges | Pay-fixed interest rate swaps | Other Liabilities
Derivatives Fair Value [Line Items]
Interest rate derivative liabilities, fair value	(13,173)	(20,383)
Derivatives not designated as hedges | Pay-fixed interest rate swaps | Other Assets
Derivatives Fair Value [Line Items]
Interest rate derivative assets, fair value	$ 10,856	$ 9,949
Derivatives not designated as hedges | Pay-variable interest rate swaps
Derivatives Fair Value [Line Items]
Weighted average fixed rate of interest rate derivatives (in Percent)	3.87%	3.77%
Weighted average remaining maturity of interest rate derivatives (in Duration)	6 years 4 months 19 days	6 years 9 months
Notional amount of interest rate derivatives	$ 1,028,041	$ 912,000
Derivatives not designated as hedges | Pay-variable interest rate swaps | Other Liabilities
Derivatives Fair Value [Line Items]
Interest rate derivative liabilities, fair value	(12,189)	(9,949)
Derivatives not designated as hedges | Pay-variable interest rate swaps | Other Assets
Derivatives Fair Value [Line Items]
Interest rate derivative assets, fair value	$ 14,410	$ 20,383
Derivatives not designated as hedges | Interest rate caps purchased, indexed to 1-month Libor [Domain]
Derivatives Fair Value [Line Items]
Weighted average fixed rate of interest rate derivatives (in Percent)	2.81%	2.96%
Weighted average remaining maturity of interest rate derivatives (in Duration)	1 year 3 months 29 days	2 years 3 months 9 days
Notional amount of interest rate derivatives	$ 145,354	$ 189,057
Derivatives not designated as hedges | Interest rate caps purchased, indexed to 1-month Libor [Domain] | Other Assets
Derivatives Fair Value [Line Items]
Interest rate derivative assets, fair value	$ 11	$ 252
Derivatives not designated as hedges | Interest rate caps sold, indexed to 1-month Libor [Domain] [Domain]
Derivatives Fair Value [Line Items]
Weighted average fixed rate of interest rate derivatives (in Percent)	2.81%	2.96%
Weighted average remaining maturity of interest rate derivatives (in Duration)	1 year 3 months 29 days	2 years 3 months 9 days
Notional amount of interest rate derivatives	$ 145,354	$ 189,057
Derivatives not designated as hedges | Interest rate caps sold, indexed to 1-month Libor [Domain] [Domain] | Other Liabilities
Derivatives Fair Value [Line Items]
Interest rate derivative liabilities, fair value	$ (11)	$ (252)

Derivatives and Hedging Activ95

Derivatives and Hedging Activities (Interest Rate Swaps Subject to Master Netting Agreements) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross Amounts Recognized, Derivative assets	$ 13,217	$ 29,849
Gross Amounts Recognized, Derivative liabilities	(13,173)	(51,362)
Gross Amounts Recognized, Derivative assets and liabilities	44	(21,513)
Gross Amounts Offset in Balance Sheet, Derivative assets	0	0
Gross Amounts Offset in Balance Sheet, Derivative liabilities	0	0
Gross Amounts Offset in Balance Sheet, Derivative assets and liabilities	0	0
Net Amounts Presented in Balance Sheet, Derivative assets	13,217	29,849
Net Amounts Presented in Balance Sheet, Derivative liabilities	(13,173)	(51,362)
Net Amounts Presented in Balance Sheet, Derivative assets and liabilities	44	(21,513)
Gross Amounts Not Offset in Balance Sheet
Derivative Instruments, Derivative assets	(7,996)	(27,485)
Derivative Instruments, Derivative liabilities	7,996	27,485
Derivative Instruments, Derivative assets and liabilities	0	0
Collateral Pledged, Derivative assets	(5,221)	0
Collateral Pledged, Derivative liabilities	4,962	23,796
Collateral Pledged, Derivative assets and liabilities	(259)	23,796
Net Amount, Derivative assets	0	2,364
Net Amount, Derivative liabilities	(215)	(81)
Net Amount, Derivative assets and liabilities	$ (215)	$ 2,283

Derivatives and Hedging Activ96

Derivatives and Hedging Activities Derivative and Hedging Activities - Amount of loss reclassified from AOCI into Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	$ (9,621)	$ (16,161)	$ (26,479)
Borrowings [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	$ (9,621)	$ (16,161)	(21,610)
Interest-bearing Deposits [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion			$ (4,869)

Stockholders' Equity (Narrative

Stockholders' Equity (Narrative) (Details) $ / shares in Units, $ in Millions	Feb. 29, 2012$ / shares$ / warrantshares	Feb. 26, 2018USD ($)
Subsequent Event [Line Items]
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Warrants Issued	1,834,160
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 9.47
Shares of common stock called by each warrant (in Shares)	0.0827
Cash amount holder entitled to receive per warrant (in Dollars per Unit) | $ / warrant	1.73
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock Repurchase Program, Authorized Amount | $		$ 150

Stockholders' Equity (Changes i

Stockholders' Equity (Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Unrealized gains on investment securities available for sale:
Net unrealized holding gain (loss) arising during the period, Before Tax	$ 49,131	$ 23,588	$ (34,470)
Amounts reclassified to gain on investment securities available for sale, net, Before Tax	(33,466)	(14,461)	(8,480)
Net change in unrealized gains on securities available for sale, Before Tax	15,665	9,127	(42,950)
Net unrealized holding gain (loss) arising during the period, Tax Effect	(19,407)	(9,317)	12,813
Amounts reclassified to gain on investment securities available for sale, net, Tax Effect	13,219	5,712	3,350
Net change in unrealized gains on securities available for sale, Tax Effect	(6,188)	(3,605)	16,163
Net unrealized holding gain (loss) arising during the period, Net of Tax	29,724	14,271	(21,657)
Amounts reclassified to gain on investment securities available for sale, net, Net of Tax	(20,247)	(8,749)	(5,130)
Net change in unrealized gains on securities available for sale	9,477	5,522	(26,787)
Unrealized losses on derivative instruments:
Net unrealized holding gain (loss) arising during the period, Before Tax	(2,577)	6,225	(22,635)
Amounts reclassified to interest expense on deposits, before tax			4,869
Net change in unrealized losses on derivative instruments, Before Tax	7,044	22,386	3,844
Net unrealized holding gain (loss) arising during the period, Tax Effect	1,018	(2,459)	9,232
Amounts reclassified to interest expense on deposits, tax effect			(1,923)
Net change in unrealized losses on derivative instruments, Tax Effect	(2,782)	(8,843)	(1,227)
Net unrealized holding gain (loss) arising during the period, Net of Tax	(1,559)	3,766	(13,403)
Amounts reclassified to interest expense on deposits, net of tax			2,946
Net change in unrealized losses on derivative instruments	4,262	13,543	2,617
Other comprehensive income (loss), Before Tax	22,709	31,513	(39,106)
Other comprehensive income (loss), Tax Effect	(8,970)	(12,448)	14,936
Other comprehensive income (loss)	13,739	19,065	(24,170)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax			21,610
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax			(8,536)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax			13,074
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	(9,621)	(16,161)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(3,800)	(6,384)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	$ (5,821)	$ (9,777)	$ (16,020)

Stockholders' Equity (Categorie

Stockholders' Equity (Categories of Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income, Beginning Balance	$ 41,247	$ 22,182	$ 46,352
Other comprehensive income (loss)	13,739	19,065	(24,170)
Other comprehensive income, Ending Balance	54,986	41,247	22,182
Unrealized Gains on Investment Securities Available for Sale
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income, Beginning Balance	47,057	41,535	68,322
Other comprehensive income (loss)	9,477	5,522	(26,787)
Other comprehensive income, Ending Balance	56,534	47,057	41,535
Unrealized Losses on Derivative Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income, Beginning Balance	(5,810)	(19,353)	(21,970)
Other comprehensive income (loss)	4,262	13,543	2,617
Other comprehensive income, Ending Balance	$ (1,548)	$ (5,810)	$ (19,353)

Equity Based Compensation (Narr

Equity Based Compensation (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 25,800	$ 900	$ 8,700
Unvested and restricted share awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 22,700
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 10 months 2 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	621,806,000	651,760	664,928
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	47,848	97,852
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards	$ 800
RSUs vesting over five years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	39,979
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	25,321		41,645
RSU and PSU Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 5,300
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 27 days
Incentive Compensation Arrangements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 3,900
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	3 years 1 day
2010 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	7,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	246,151
2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,892,439
Deferred Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of elective deferrals which vest immediately (in Percent)	100.00%
Percent of matching contributions which vest upon the earlier of a defined change in control or the participant's death, disability, attainment of normal retirement age, or the completion of two years of service (in Percent)			100.00%
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 1,458	$ 1,500	$ 751
401(k) Plan, First 1% Of Eligible Compensation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Arrangement with Individual, Cash Awards Granted, Percentage	100.00%
401(k) Plan, 2% To 6% Of Eligible Compensation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Arrangement with Individual, Cash Awards Granted, Percentage	70.00%
401(k) Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of employer contributions (in Duration)	2 years
Deferred Compensation Arrangement with Individual, Contributions by Employer	$ 5,500	5,200	$ 4,900
Other Liabilities | RSU and PSU Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Share-based Arrangements, Liability, Current and Noncurrent	3,900
Other Liabilities | Incentive Compensation Arrangements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Share-based Arrangements, Liability, Current and Noncurrent	1,300
Other Liabilities | Deferred Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred Compensation Liability, Current and Noncurrent	$ 21,000	$ 20,000

Equity Based Compensation (Sche

Equity Based Compensation (Schedule of Compensation Costs Related to Equity Based Awards) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 22,792	$ 18,367	$ 15,867
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	(8,576)	(6,899)	(5,965)
Allocated Share-based Compensation Expense, Net of Tax	14,216	11,468	9,902
Unvested and restricted share awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	18,087	16,885	15,573
RSU and PSU Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	3,416	1,482	294
Incentive Compensation Arrangements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 1,289	$ 0	$ 0

Equity Based Compensation (S102

Equity Based Compensation (Schedule of Nonvested Share Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Range of the closing price on date of grant, minimum (in Dollars per Share)		$ 33.21	$ 29.78	$ 31.35
Range of the closing price on date of grant, maximum (in Dollars per Share)		$ 40.84	$ 33.76	$ 38.63
Aggregate grant date fair value of shares vesting	$ 17,514	$ 13,613	$ 11,330
Unvested and restricted share awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	1,108,477,000	1,120,700	1,040,385	829,225
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 36.06	$ 31.46	$ 31.86	$ 30.06
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	621,806,000	651,760	664,928
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 40.24	$ 31	$ 32.06
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(553,007,000)	(428,167)	(394,498)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 31.67	$ 31.79	$ 28.72
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures and Expirations	(81,022,000)	(143,278)	(59,270)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 34.51	$ 31.31	$ 29.82

Equity Based Compensation Sched

Equity Based Compensation Schedule of Other Share-Based Compensation, Activity (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	47,848	97,852
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	35,241	19,291
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	91,168	78,561	0
Performance share units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	47,848	57,873
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	105,721	57,873	0

Equity Based Compensation (S104

Equity Based Compensation (Schedule of Stock Options Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	1,270,688
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	1,270,688	3,602,076	3,651,152	5,015,047
Number of Option Awards
Exercised (in Shares)	(2,331,388)	(47,979)	(1,363,895)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period		(1,097)
Weighted Average Exercise Price
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 26.63	$ 16.50	$ 26.14
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	26.93	26.74	$ 26.62	$ 26.49
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price		$ 63.74
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 26.93

Equity Based Compensation (S105

Equity Based Compensation (Schedule of Options Outstanding and Exercisable, Additional Information) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | shares	1,270,688
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	3 years 16 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 17,889
Exercise Price Range 11.14 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 11.14
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 11.14
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | shares	13,160
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	1 year 8 months 22 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 389
Exercise Price Range 15.94-19.97 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 15.94
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 19.97
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | shares	29,145
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	2 years 7 months 4 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 672
Exercise Price Range 22.18-22.31 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 22.18
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 22.31
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | shares	41,417
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	3 years 5 months 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 764
Exercise Price 27.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 27
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 27
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | shares	1,170,847
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	3 years 1 month
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 16,064
Exercise Price 63.74 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 63.74
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 63.74
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options | shares	16,119
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	11 months 4 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 0

Regulatory Requirements and 106

Regulatory Requirements and Restrictions (Schedule of Compliance with Regulatory Capital Requirements Under Banking Regulations) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Leverage Capital	$ 2,892,069	$ 2,298,450
Tier One Leverage Capital to Average Assets	9.72%	8.41%
Tier One Leverage Capital Required for Capital Adequacy	$ 1,189,944	$ 1,092,921
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Common Equity Tier One Risk Based Capital	$ 2,892,069	$ 2,298,450
Common Equity Tier One Risk Based Capital to Risk Weighted Assets	13.11%	11.63%
Common Equity Tier One Risk Based Capital Required to be Well Capitalized	$ 1,434,193	$ 1,284,498
Common Equity Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Common Equity Tier One Risk Based Capital Required for Capital Adequacy	$ 992,903	$ 889,268
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Risk Based Capital	$ 2,892,069	$ 2,298,450
Tier One Risk Based Capital to Risk Weighted Assets	13.11%	11.63%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,765,161	$ 1,580,921
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	$ 1,323,871	$ 1,185,691
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Capital	$ 3,041,004	$ 2,459,470
Capital to Risk Weighted Assets	13.78%	12.45%
Capital Required to be Well Capitalized	$ 2,206,451	$ 1,976,151
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Capital Required to be Well Capitalized to Risk Weighted Assets	$ 1,765,161	$ 1,580,921
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
BankUnited [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier One Leverage Capital	$ 3,107,920	$ 2,534,402
Tier One Leverage Capital to Average Assets	10.47%	9.30%
Tier One Leverage Capital Required to be Well Capitalized	$ 1,483,796	$ 1,361,959
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Tier One Leverage Capital Required for Capital Adequacy	$ 1,187,037	$ 1,089,567
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Common Equity Tier One Risk Based Capital	$ 3,107,920	$ 2,534,402
Common Equity Tier One Risk Based Capital to Risk Weighted Assets	14.13%	12.89%
Common Equity Tier One Risk Based Capital Required to be Well Capitalized	$ 1,429,999	$ 1,278,277
Common Equity Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Common Equity Tier One Risk Based Capital Required for Capital Adequacy	$ 989,999	$ 884,961
Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier One Risk Based Capital	$ 3,107,920	$ 2,534,402
Tier One Risk Based Capital to Risk Weighted Assets	14.13%	12.89%
Tier One Risk Based Capital Required to be Well Capitalized	$ 1,759,999	$ 1,573,265
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	$ 1,319,999	$ 1,179,948
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Capital	$ 3,255,221	$ 2,694,048
Capital to Risk Weighted Assets	14.80%	13.70%
Capital Required to be Well Capitalized	$ 2,199,999	$ 1,966,581
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Capital Required to be Well Capitalized to Risk Weighted Assets	$ 1,759,999	$ 1,573,265
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%

Regulatory Requirements and 107

Regulatory Requirements and Restrictions (Narrative) (Details) $ in Millions	Dec. 31, 2017USD ($)
Banking and Thrift [Abstract]
Ratio that the FDIC indemnification asset and the covered assets are risk-weighted at (in Percent)	20.00%
FRB net reserve requirement	$ 91

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	$ 6,739,196	$ 6,150,975
Liabilities at fair value	25,373	61,562
Derivative Financial Instruments, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities at fair value	25,373	61,562
US Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	24,953	5,005
U.S. Government agency and sponsored enterprise residential MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	2,058,027	1,527,242
U.S. Government agency and sponsored enterprise commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	234,508	124,586
Private label residential mortgage-backed securities and CMOs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	628,247	375,098
Private label commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	1,046,415	1,187,624
Single family rental real estate-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	562,706	861,251
Collateralized loan obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	723,681	487,296
Non-mortgage asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	121,747	186,736
Preferred stocks
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	63,543	88,203
State and municipal obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	657,203	698,546
SBA securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	550,682	523,906
Other debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	9,120	8,091
Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	30,737	27,159
Derivative Financial Instruments, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	27,627	50,232
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	88,496	91,895
Fair Value, Inputs, Level 1 | US Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	24,953	5,005
Fair Value, Inputs, Level 1 | Preferred stocks
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	63,543	86,890
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	6,562,420	5,906,739
Liabilities at fair value	25,373	61,562
Fair Value, Inputs, Level 2 | Derivative Financial Instruments, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities at fair value	25,373	61,562
Fair Value, Inputs, Level 2 | U.S. Government agency and sponsored enterprise residential MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	2,058,027	1,527,242
Fair Value, Inputs, Level 2 | U.S. Government agency and sponsored enterprise commercial MBS
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	234,508	124,586
Fair Value, Inputs, Level 2 | Private label residential mortgage-backed securities and CMOs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	576,033	254,488
Fair Value, Inputs, Level 2 | Private label commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	1,046,415	1,187,624
Fair Value, Inputs, Level 2 | Single family rental real estate-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	562,706	861,251
Fair Value, Inputs, Level 2 | Collateralized loan obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	723,681	487,296
Fair Value, Inputs, Level 2 | Non-mortgage asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	121,747	186,736
Fair Value, Inputs, Level 2 | Preferred stocks
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	0	1,313
Fair Value, Inputs, Level 2 | State and municipal obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	657,203	698,546
Fair Value, Inputs, Level 2 | SBA securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	550,682	523,906
Fair Value, Inputs, Level 2 | Other debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	3,791	3,519
Fair Value, Inputs, Level 2 | Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	0	0
Fair Value, Inputs, Level 2 | Derivative Financial Instruments, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	27,627	50,232
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	88,280	152,341
Liabilities at fair value	0	0
Fair Value, Inputs, Level 3 | Derivative Financial Instruments, Liabilities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities at fair value	0	0
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMOs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	52,214	120,610
Fair Value, Inputs, Level 3 | Other debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	5,329	4,572
Fair Value, Inputs, Level 3 | Servicing Rights [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	30,737	27,159
Fair Value, Inputs, Level 3 | Derivative Financial Instruments, Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets, fair value	$ 0	$ 0

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2016
Fair Value Inputs Assets Quantitative Information [Line Items]
Asset transfers	$ 0	$ 0
Balance of residential mortgage servicing rights which the Company elected to measure at fair value				$ 8,500
Assets, fair value	6,739,196	6,150,975
Servicing Rights [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	(1,000)	(1,800)
Assets, fair value	30,737	27,159
Other debt securities
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	9,120	8,091
Private label residential mortgage-backed securities and CMOs
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	628,247	375,098
Impaired Loans [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets with Nonrecurring Changes in Fair Value	93,051	78,121	$ 30,812
Gains (Losses) from Nonrecurring Fair Value Changes	(65,716)	(25,573)	(9,865)
OREO and Repossessed Assets [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets with Nonrecurring Changes in Fair Value	5,790	12,466	7,389
Gains (Losses) from Nonrecurring Fair Value Changes	(2,078)	(1,156)	(1,206)
Fair Value, Inputs, Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	88,280	152,341
Fair Value, Inputs, Level 3 | Servicing Rights [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	30,737	27,159
Fair Value, Inputs, Level 3 | Other debt securities
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	5,329	4,572
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMOs
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	52,214	120,610
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Investment grade
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	$ 32,997
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Investment grade | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Current subordination level (in Percent)	17.30%
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Non-investment grade
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets, fair value	$ 19,217
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Non-investment grade | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Current subordination level (in Percent)	9.70%
Fair Value, Inputs, Level 3 | Impaired Loans [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets with Nonrecurring Changes in Fair Value	$ 93,051	78,121	30,812
Fair Value, Inputs, Level 3 | OREO and Repossessed Assets [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets with Nonrecurring Changes in Fair Value	5,790	12,466	$ 7,389
Taxi medallion [Member] | Impaired Loans [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Gains (Losses) from Nonrecurring Fair Value Changes	62,400	12,700
Taxi medallion [Member] | OREO and Repossessed Assets [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Gains (Losses) from Nonrecurring Fair Value Changes	(1,300)	(200)
Taxi medallion [Member] | Fair Value, Inputs, Level 3 | Impaired Loans [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets with Nonrecurring Changes in Fair Value	86,000	50,700
Taxi medallion [Member] | Fair Value, Inputs, Level 3 | OREO and Repossessed Assets [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Assets with Nonrecurring Changes in Fair Value	$ 2,100	$ 2,500

Fair Value Measurements (Change

Fair Value Measurements (Changes in the Fair Value of Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Document Fiscal Year Focus	2,017
Private label residential mortgage-backed securities and CMOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period, fair value of assets	$ 120,610	$ 140,883	$ 168,077
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	25,547	0	0
Gains (losses) for the period included in Other comprehensive income (loss)	(27,569)	(2,229)	(7,469)
Amortization	6,181	5,947	6,524
Sales	(45,524)
Settlements	(27,031)	(23,991)	(26,249)
Balance at end of period, fair value of assets	52,214	120,610	140,883
Other debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period, fair value of assets	4,572	4,532	4,918
Gains (losses) for the period included in Other comprehensive income (loss)	766	(9)	(434)
Amortization	280	116	148
Settlements	(289)	(67)	(100)
Balance at end of period, fair value of assets	5,329	4,572	4,532
Commercial Servicing Rights [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period, fair value of assets		11,548	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			(2,062)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases			13,610
Balance at end of period, fair value of assets			11,548
Servicing Rights [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period, fair value of assets	27,159	20,017
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	(5,821)	(6,023)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	9,399	13,165
Balance at end of period, fair value of assets	$ 30,737	$ 27,159	$ 20,017

Fair Value Measurements (Valuat

Fair Value Measurements (Valuation Techniques and Unobservable Inputs Used in the Valuation of Financial Instruments Falling within Level 3 of the Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	$ 6,739,196	$ 6,150,975
Private label residential mortgage-backed securities and CMO's - Investment grade | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	9.00%
Probability rate of default	0.00%
Loss severity	15.00%
Fair Value Inputs, Discount Rate	1.68%
Private label residential mortgage-backed securities and CMO's - Investment grade | Discounted cash flow | Maximum [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	27.80%
Probability rate of default	4.10%
Loss severity	86.00%
Fair Value Inputs, Discount Rate	8.11%
Private label residential mortgage-backed securities and CMO's - Investment grade | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	16.94%
Probability rate of default	1.18%
Loss severity	30.56%
Fair Value Inputs, Discount Rate	3.64%
Private label residential mortgage-backed securities and CMO's - Non-investment grade | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	0.70%
Probability rate of default	0.00%
Loss severity	15.00%
Fair Value Inputs, Discount Rate	2.31%
Private label residential mortgage-backed securities and CMO's - Non-investment grade | Discounted cash flow | Maximum [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	27.80%
Probability rate of default	7.00%
Loss severity	83.00%
Fair Value Inputs, Discount Rate	9.13%
Private label residential mortgage-backed securities and CMO's - Non-investment grade | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	15.37%
Probability rate of default	2.00%
Loss severity	31.04%
Fair Value Inputs, Discount Rate	6.03%
Residential Servicing Rights [Member] | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	7.31%
Fair Value Inputs, Discount Rate	9.50%
Residential Servicing Rights [Member] | Discounted cash flow | Maximum [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	26.98%
Fair Value Inputs, Discount Rate	9.58%
Residential Servicing Rights [Member] | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	12.12%
Fair Value Inputs, Discount Rate	9.51%
Commercial Servicing Rights [Member] | Discounted cash flow | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	0.66%
Fair Value Inputs, Discount Rate	8.41%
Commercial Servicing Rights [Member] | Discounted cash flow | Maximum [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	10.99%
Fair Value Inputs, Discount Rate	15.26%
Commercial Servicing Rights [Member] | Discounted cash flow | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair Value Inputs, Prepayment Rate	8.79%
Fair Value Inputs, Discount Rate	12.69%
Fair Value, Inputs, Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	$ 88,280	$ 152,341
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Investment grade
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	32,997
Fair Value, Inputs, Level 3 | Private label residential mortgage-backed securities and CMO's - Non-investment grade
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	19,217
Fair Value, Inputs, Level 3 | Residential Servicing Rights [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	19,622
Fair Value, Inputs, Level 3 | Commercial Servicing Rights [Member]
Fair Value Inputs Assets Quantitative Information [Line Items]
Total fair value of assets	$ 11,115

Fair Value Measurements (Ass112

Fair Value Measurements (Assets for which Nonrecurring Changes in Fair Value have been Recorded) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value Inputs, Average fare per trip (Taxi Medallion)	$ 16.04
Fair Value Inputs, Number of trips per shift (Taxi Medallion)	15.3
Fair Value Inputs, Days Worked per Month (Taxi Medallion)	25.9
Fair Value Inputs, Second Shift Rental Achievement Rate (Taxi Medallion)	53.90%
OREO and Repossessed Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value	$ 5,790,000	$ 12,466,000	$ 7,389,000
Gains (Losses) from Nonrecurring Fair Value Changes	(2,078,000)	(1,156,000)	(1,206,000)
OREO and Repossessed Assets [Member] | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value	5,790,000	12,466,000	7,389,000
Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value	93,051,000	78,121,000	30,812,000
Gains (Losses) from Nonrecurring Fair Value Changes	(65,716,000)	(25,573,000)	(9,865,000)
Impaired Loans [Member] | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value	93,051,000	78,121,000	30,812,000
Property Subject to Operating Lease [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value		8,173,000
Gains (Losses) from Nonrecurring Fair Value Changes		(4,100,000)
Property Subject to Operating Lease [Member] | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value		8,173,000
Residential Servicing Rights [Member] [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value			8,469,000
Gains (Losses) from Nonrecurring Fair Value Changes			(15,000)
Residential Servicing Rights [Member] [Member] | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value			$ 8,469,000
Taxi medallion [Member] | OREO and Repossessed Assets [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gains (Losses) from Nonrecurring Fair Value Changes	(1,300,000)	(200,000)
Taxi medallion [Member] | OREO and Repossessed Assets [Member] | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value	2,100,000	2,500,000
Taxi medallion [Member] | Impaired Loans [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gains (Losses) from Nonrecurring Fair Value Changes	62,400,000	12,700,000
Taxi medallion [Member] | Impaired Loans [Member] | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets with Nonrecurring Changes in Fair Value	$ 86,000,000	$ 50,700,000

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Value and Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Investment securities available for sale	$ 6,680,832	$ 6,073,584
Non-marketable equity securities	265,989	284,272
Loans and Leases Receivable, Net Amount	20,768,849	18,630,499
FDIC indemnification asset	295,635	515,933
Derivative assets	0	2,364
Liabilities:
Time Deposits	6,334,842	5,755,642
Derivative liabilities	215	81
Fair Value, Inputs, Level 1
Assets:
Cash and cash equivalents	194,582	448,313
Fair Value, Inputs, Level 2
Assets:
Non-marketable equity securities	265,989	284,272
Loans held for sale	37,847	45,833
Derivative assets	27,627	50,232
Liabilities:
Demand, savings and money market deposits	15,543,637	13,735,248
Time Deposits	6,324,010	5,759,787
FHLB advances	4,774,160	5,244,188
Notes Payable, Fair Value Disclosure	435,361	403,733
Derivative liabilities	25,373	61,562
Fair Value, Inputs, Level 3
Assets:
Investment securities held to maturity	10,000	10,000
Loans and Leases Receivable, Net Reported Amount, Covered	922,888	1,200,291
Loans and Leases Receivable, Net Amount	20,759,567	18,713,495
FDIC indemnification asset	148,356	256,691
Carrying Value
Assets:
Cash and cash equivalents	194,582	448,313
Investment securities available for sale	6,680,832	6,073,584
Investment securities held to maturity	10,000	10,000
Non-marketable equity securities	265,989	284,272
Loans held for sale	34,097	41,198
Loans and Leases Receivable, Net Reported Amount, Covered	502,860	611,942
Loans and Leases Receivable, Net Amount	20,768,849	18,630,499
FDIC indemnification asset	295,635	515,933
Derivative assets	27,627	50,232
Liabilities:
Demand, savings and money market deposits	15,543,637	13,735,248
Time Deposits	6,334,842	5,755,642
FHLB advances	4,771,000	5,239,348
Notes Payable, Fair Value Disclosure	402,830	402,809
Derivative liabilities	$ 25,373	$ 61,562

Commitments and Contingencie114

Commitments and Contingencies (Total Lending Related Commitments Outstanding) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Lending Related Commitments [Line Items]
Unused Commitments to Extend Credit	$ 3,138,850
Commitments to fund loans
Lending Related Commitments [Line Items]
Unused Commitments to Extend Credit	376,525
Commitments to purchase loans
Lending Related Commitments [Line Items]
Unused Commitments to Extend Credit	401,270
Unfunded commitments under lines of credit [Member]
Lending Related Commitments [Line Items]
Unused Commitments to Extend Credit	2,278,201
Commercial and standby letters of credit
Lending Related Commitments [Line Items]
Unused Commitments to Extend Credit	$ 82,854

Condensed Financial Statemen115

Condensed Financial Statements of BankUnited, Inc. (Schedule of Condensed Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets:
Cash and cash equivalents	$ 194,582	$ 448,313	$ 267,500	$ 187,517
Investment securities available for sale, at fair value	6,680,832	6,073,584
Other assets	664,382	406,713
Total assets	30,346,986	27,880,151
Liabilities and Stockholders' Equity:
Liabilities	27,320,924	25,461,722
Stockholders' equity	3,026,062	2,418,429	2,243,898	2,052,534
Total liabilities and stockholders' equity	30,346,986	27,880,151
Parent Company [Member]
Assets:
Cash and cash equivalents	131,696	87,718	$ 82,810	$ 178,444
Investment securities available for sale, at fair value	63,543	78,293
Investment in subsidiaries	3,239,717	2,652,535
Deferred tax asset, net	9,456	16,738
Other assets	8,462	5,345
Total assets	3,452,874	2,840,629
Liabilities and Stockholders' Equity:
Notes Payable	393,725	393,092
Liabilities	33,087	29,108
Stockholders' equity	3,026,062	2,418,429
Total liabilities and stockholders' equity	$ 3,452,874	$ 2,840,629

Condensed Financial Statemen116

Condensed Financial Statements of BankUnited, Inc. (Schedule of Condensed Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Interest Expense - Borrowings									$ 83,256	$ 69,059	$ 44,013
Employee compensation and benefits									237,824	223,011	210,104
Income before income taxes	$ 118,922	$ 100,031	$ 95,428	$ 90,080	$ 92,101	$ 74,398	$ 84,722	$ 84,223	404,461	335,444	296,893
Provision for income taxes	(298,872)	32,252	29,021	27,787	28,807	23,550	27,997	29,349	(209,812)	109,703	45,233
Net income	$ 417,794	$ 67,779	$ 66,407	$ 62,293	$ 63,294	$ 50,848	$ 56,725	$ 54,874	614,273	225,741	251,660
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Interest and Dividend Income - Investment securities									3,580	4,280	4,866
Service fees from subsidiaries									18,787	21,957	17,404
Equity in earnings of subsidiaries									639,250	242,874	256,456
Other Income									0	0	235
Total Income									661,617	269,111	278,961
Interest Expense - Borrowings									20,132	20,100	2,457
Employee compensation and benefits									27,032	27,143	22,099
Other expense									5,047	4,466	4,356
Total expense									52,211	51,709	28,912
Income before income taxes									609,406	217,402	250,049
Provision for income taxes									(4,867)	(8,339)	(1,611)
Net income									$ 614,273	$ 225,741	$ 251,660

Condensed Financial Statemen117

Condensed Financial Statements of BankUnited, Inc. (Schedule of Condensed Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	$ 417,794	$ 67,779	$ 66,407	$ 62,293	$ 63,294	$ 50,848	$ 56,725	$ 54,874	$ 614,273	$ 225,741	$ 251,660
Adjustments to reconcile net income to net cash provided by operating activities:
Equity based compensation									22,692	18,032	16,027
Net cash provided by operating activities									318,626	308,510	219,479
Cash flows from investing activities:
Purchase of investment securities available for sale									(3,131,798)	(3,058,106)	(2,093,508)
Proceeds from repayments and calls of investment securities available for sale									1,260,444	724,666	537,992
Other									(37,161)	(24,960)	(24,020)
Net cash used in investing activities									(2,452,576)	(3,826,231)	(4,608,692)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt									0	0	392,252
Dividends paid									(91,628)	(89,824)	(88,981)
Exercise of stock options									62,095	791	35,647
Other									(8,837)	5,178	3,873
Net cash provided by financing activities									1,880,219	3,698,534	4,469,196
Net increase (decrease) in cash and cash equivalents									(253,731)	180,813	79,983
Cash and cash equivalents, beginning of period				448,313				267,500	448,313	267,500	187,517
Cash and cash equivalents, end of period	194,582				448,313				194,582	448,313	267,500
Supplemental schedule of non-cash investing and financing activities:
Dividends declared, not paid									23,055	22,510	22,380
Parent Company [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income									614,273	225,741	251,660
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries									(519,250)	(157,374)	(176,456)
Equity based compensation									22,692	18,032	16,027
Increase (Decrease) in Other Operating Assets and Liabilities, Net									3,343	7,438	1,878
Net cash provided by operating activities									121,058	93,837	93,109
Cash flows from investing activities:
Capital contributions to subsidiary									55,000	0	575,000
Purchase of investment securities available for sale									0	(20,150)
Proceeds from repayments and calls of investment securities available for sale									15,000	19,401	46,031
Other									(250)	(3)	(285)
Net cash used in investing activities									(40,250)	(752)	(529,254)
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt									0	0	392,252
Dividends paid									(91,628)	(89,824)	(88,981)
Exercise of stock options									62,095	791	35,647
Other									(7,297)	856	1,593
Net cash provided by financing activities									(36,830)	(88,177)	340,511
Net increase (decrease) in cash and cash equivalents									43,978	4,908	(95,634)
Cash and cash equivalents, beginning of period				$ 87,718				$ 82,810	87,718	82,810	178,444
Cash and cash equivalents, end of period	$ 131,696				$ 87,718				131,696	87,718	82,810
Supplemental schedule of non-cash investing and financing activities:
Dividends declared, not paid									$ 23,055	$ 22,510	$ 22,380

Condensed Financial Statemen118

Condensed Financial Statements of BankUnited, Inc. (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Dividends Paid to Parent Company by Consolidated Subsidiaries	$ (120)	$ (86)	$ (80)

Quarterly Financial Informat119

Quarterly Financial Information (Unaudited) (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Interest and Dividend Income, Operating	$ 312,645	$ 309,443	$ 298,835	$ 283,538	$ 277,965	$ 269,981	$ 260,464	$ 250,807	$ 1,204,461	$ 1,059,217	$ 880,816
Interest Expense	73,819	68,179	59,246	52,945	50,466	48,246	46,154	43,966	254,189	188,832	135,164
Interest Income (Expense), Net	238,826	241,264	239,589	230,593	227,499	221,735	214,310	206,841	950,272	870,385	745,652
Provision for loan losses	5,174	37,854	13,619	12,100	8,462	24,408	14,333	3,708	68,747	50,911	44,311
Interest Income (Expense), after Provision for Loan Loss	233,652	203,410	225,970	218,493	219,037	197,327	199,977	203,133	881,525	819,474	701,341
Noninterest Income	46,541	53,326	29,893	28,144	29,287	25,075	28,857	23,198	157,904	106,417	102,224
Noninterest Expense	161,271	156,705	160,435	156,557	156,223	148,004	144,112	142,108	634,968	590,447	506,672
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	118,922	100,031	95,428	90,080	92,101	74,398	84,722	84,223	404,461	335,444	296,893
Provision for income taxes	(298,872)	32,252	29,021	27,787	28,807	23,550	27,997	29,349	(209,812)	109,703	45,233
Net income	$ 417,794	$ 67,779	$ 66,407	$ 62,293	$ 63,294	$ 50,848	$ 56,725	$ 54,874	$ 614,273	$ 225,741	$ 251,660
Earnings Per Share, Basic	$ 3.80	$ 0.62	$ 0.60	$ 0.57	$ 0.59	$ 0.47	$ 0.53	$ 0.51	$ 5.60	$ 2.11	$ 2.37
Earnings Per Share, Diluted	$ 3.79	$ 0.62	$ 0.60	$ 0.57	$ 0.59	$ 0.47	$ 0.52	$ 0.51	$ 5.58	$ 2.09	$ 2.35
Discrete Income Tax Benefit									$ 327,945	$ 0	$ 49,323