Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INTEREST AND DIVIDEND INCOME
Loan receivable	$ 677,193	$ 729,619	$ 652,480
Investment securities	20,599	33,037	28,603
Federal Home Loan Bank stock	952	1,207	1,663
Deposits with banks	1,830	5,404	5,209
Total interest and dividend income	700,574	769,267	687,955
INTEREST EXPENSE
Time deposits	111,629	152,791	86,368
Other deposits	25,396	25,311	20,503
Interest on securities sold under agreements to repurchase	0	0	1,446
Advances from the Federal Home Loan Bank	5,299	7,441	3,739
Long-term debt	5,791	7,847	8,723
Deferred payments from acquisition	115	568	1,090
Short-term borrowings	234	403	187
Total interest expense	148,464	194,361	122,056
Net interest income before provision/(reversal) for credit losses	552,110	574,906	565,899
Provision/(reversal) for credit losses	(57,500)	7,000	4,500
Net interest income after provision/(reversal) for credit losses	494,610	581,906	570,399
NON-INTEREST INCOME
Net (losses)/gains from equity securities	(1,148)	5,736	(2,787)
Securities gains, net	1,695	211	22
Letters of credit commissions	6,741	6,407	5,614
Depository service fees	4,949	4,763	5,084
Gain from acquisition	0	0	340
Other operating income	30,583	27,634	23,434
Total non-interest income	42,820	44,751	31,707
NON-INTEREST EXPENSE
Salaries and employee benefits	124,022	129,300	124,477
Occupancy expense	20,634	22,004	20,690
Computer and equipment expense	11,133	11,113	11,402
Professional services expense	21,856	23,107	22,810
Data processing service expense	14,897	13,210	12,438
FDIC and State assessments	8,999	9,617	8,000
Marketing expense	5,224	7,585	7,837
Other real estate owned (income)/loss	(3,091)	1,115	(719)
Operations of investments in affordable housing and alternative energy partnerships, net	58,225	39,731	40,515
Amortization of core deposit premium	687	687	876
Acquisition and integration costs	0	0	2,105
Cost associated with debt redemption	693	0	0
Other operating expense	20,186	19,819	13,988
Total non-interest expense	283,465	277,288	264,419
Income before income tax expense	253,965	349,369	337,687
Income tax expense	25,105	70,234	65,802
Net income attributable to common stockholders	228,860	279,135	271,885
Other comprehensive income/(loss), net of tax:
Unrealized holding gains/(losses) on securities available for sale	7,680	23,628	(7,934)
Unrealized holding (losses)/gains on cash flow hedge derivatives	(3,478)	(3,171)	1,525
Less: reclassification adjustment for gains included in net income	1,194	149	15
Total other comprehensive income/(loss), net of tax	3,008	20,308	(6,424)
Total comprehensive income	$ 231,868	$ 299,443	$ 265,461
Basic (in dollars per share)	$ 2.88	$ 3.49	$ 3.35
Diluted (in dollars per share)	$ 2.87	$ 3.48	$ 3.33
Basic average common shares outstanding (in shares)	79,584,560	79,999,703	81,131,269
Diluted average common shares outstanding (in shares)	79,777,847	80,247,893	81,607,346