Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest and Dividend Income
Loans receivable, including loan fees		$ 168,179	$ 146,383	$ 478,128	$ 401,129
Investment securities		7,546	5,692	21,212	14,817
Federal Home Loan Bank stock		303	607	1,079	1,317
Term federal funds sold			108		108
Deposits with banks		838	1,288	3,667	3,140
Total interest and dividend income		176,866	154,078	504,086	420,511
Interest Expense
Time deposits		22,135	11,678	56,593	33,429
Other deposits		5,474	5,101	14,892	14,245
Securities sold under agreements to repurchase		124	874	1,446	3,489
Advances from Federal Home Loan Bank		1,430	872	3,286	1,465
Long-term debt		2,220	1,456	6,465	4,320
Deferred payments from acquisition		399	901	946	901
Total interest expense		31,782	20,882	83,628	57,849
Net interest income before reversal for credit losses		145,084	133,196	420,458	362,662
Reversal for credit losses		(1,500)		(4,500)	(2,500)
Net interest income after reversal for credit losses		146,584	133,196	424,958	365,162
Non-Interest Income
Net gains/(losses) from equity securities		391		(4,580)
Securities (losses)/gains, net		(14)	24	(14)	(439)
Letters of credit commissions		1,459	1,302	4,110	3,618
Depository service fees		6,931	6,502	20,813	19,161
Gain from acquisition			5,440	340	5,440
Other operating income		4,780	4,788	17,151	12,953
Total non-interest income	[1]	7,835	12,961	20,912	25,831
Non-Interest Expense
Salaries and employee benefits		30,514	27,913	91,491	79,929
Occupancy expense		5,186	5,312	15,808	14,733
Computer and equipment expense		2,772	2,643	8,477	7,895
Professional services expense		5,286	4,942	17,055	14,541
Data processing service expense		3,080	2,918	9,450	7,846
FDIC and regulatory assessments		2,555	2,552	6,732	7,261
Marketing expense		1,263	2,103	5,521	4,833
Other real estate owned (income)/expense		(21)	369	(236)	747
Amortization of investments in low income housing and alternative energy partnerships		11,115	5,723	21,989	16,797
Amortization of core deposit intangibles		190	281	704	626
Acquisition and integration costs		179	3,277	2,083	3,277
Other operating expense		3,845	3,215	10,949	11,307
Total non-interest expense		65,964	61,248	190,023	169,792
Income before income tax expense		88,455	84,909	255,847	221,201
Income tax expense		18,698	35,163	48,610	71,099
Net income		69,757	49,746	207,237	150,102
Other comprehensive income, net of tax
Unrealized holding (losses)/gains on securities available-for-sale		(2,538)	1,060	(16,803)	3,338
Unrealized holding gain/(loss) on cash flow hedge derivatives		1,666	157	4,595	(94)
Less: reclassification adjustments for (losses)/gains included in net income		(10)	14	(10)	(254)
Total other comprehensive gain, net of tax		(862)	1,203	(12,198)	3,498
Total other comprehensive income		$ 68,895	$ 50,949	$ 195,039	$ 153,600
Net income per common share:
Basic (in dollars per share)		$ 0.86	$ 0.62	$ 2.55	$ 1.87
Diluted (in dollars per share)		0.85	0.61	2.53	1.86
Cash dividends paid per common share (in dollars per share)		$ 0.24	$ 0.21	$ 0.72	$ 0.63
Weighted-average shares:
Basic (in shares)		81,311,899	80,665,398	81,224,555	80,073,249
Diluted weighted-average number of common shares outstanding (in shares)		81,855,271	81,404,854	81,770,874	80,797,179
Deposit Account [Member]
Non-Interest Income
Depository service fees		$ 1,219	$ 1,407	$ 3,905	$ 4,259

[1] There were no adjustments to the Company's financial statements recorded as a result of the adoption of ASC 606. For comparability, the Company has adjusted prior period amounts to conform to the periods presentation.