CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
INTEREST INCOME:
Loans receivable	$ 413,370	$ 374,449	$ 359,612
Mortgage-backed securities	35,076	24,535	19,328
Securities and cash equivalents	15,186	13,300	12,537
Total interest income	463,632	412,284	391,477
INTEREST EXPENSE:
Deposits	20,642	12,273	11,105
FHLB advances	5,636	1,908	953
Other borrowings	245	317	310
Junior subordinated debentures	6,136	4,752	4,040
Total interest expense	32,659	19,250	16,408
Net interest income before provision for loan losses	430,973	393,034	375,069
PROVISION FOR LOAN LOSSES	8,500	8,000	6,030
Net interest income	422,473	385,034	369,039
NON-INTEREST INCOME
Total Deposit Fees and Other Service Charges	48,074	43,452	41,911
Bank Owned Life Insurance Income	4,505	4,618	4,538
Miscellaneous	7,148	8,985	6,001
Other operating income	81,070	77,935	78,002
Net (loss) gain on sale of securities	(837)	(2,080)	843
Net change in valuation of financial instruments carried at fair value	3,775	(2,844)	(2,620)
Gain on sale of branches, including related loans and deposits	0	12,189	0
Total non-interest income	84,008	85,200	76,225
NON-INTEREST EXPENSE:
Income before provision for income taxes	165,110	151,264	129,640
PROVISION FOR INCOME TAXES	28,595	90,488	44,255
NET INCOME	136,515	60,776	85,385
Salary and employee benefits	202,613	192,096	180,883
Less capitalized loan origination costs	(17,925)	(17,379)	(18,895)
Occupancy and equipment	49,215	47,866	45,000
Information/computer data services	18,823	17,245	19,281
Payment and card processing expenses	15,412	14,330	14,359
Professional and legal expenses	17,945	17,534	8,120
Advertising and marketing	8,346	8,637	9,709
Deposit insurance	4,446	4,689	4,551
State/municipal business and use taxes	3,284	2,594	3,516
REO operations	804	(2,030)	175
Amortization of core deposit intangibles	6,047	6,246	7,061
Miscellaneous	26,754	27,142	30,131
Total other operating expense, before acquisition related costs	335,764	318,970	303,891
Acquisition related costs	5,607	0	11,733
Total non-interest expense	$ 341,371	$ 318,970	$ 315,624
Earnings per common share
Basic (in dollars per share)	$ 4.16	$ 1.85	$ 2.52
Diluted (in dollars per share)	4.15	1.84	2.52
Cumulative dividends declared per common share (in dollars per share)	$ 1.96	$ 2.00	$ 0.88
Weighted average number of common shares outstanding:
Basic	32,784,724	32,888,007	33,820,148
Diluted	32,894,425	32,986,707	33,853,511
Mortgage Banking [Member]
NON-INTEREST INCOME
Mortgage banking operations	$ 21,343	$ 20,880	$ 25,552