CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated (Deficit)	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Beginning balance at Dec. 31, 2018	$ 49	$ 1,080,084	$ (72,167)	$ (6,812)	$ (6,190)	$ 994,964
Beginning Balance (in shares) at Dec. 31, 2018	48,874,836
Increase (decrease) in shareholders' equity
Net income			25,469			25,469
Other comprehensive income (loss)				8,407		8,407
Issuance of treasury stock for employee stock purchase plan		50			222	272
Issuance of treasury stock for employee stock purchase plan (in shares)	11,731
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax		(171)			171
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax (in shares)	9,070
Net issuance of treasury stock for stock options exercised, net of shares redeemed and related tax		(72)			72
Net issuance of treasury stock for stock options exercised, net of shares redeemed and related tax (in shares)	3,838
Cash dividends common stock			(10,266)			(10,266)
Stock dividend equivalents restricted stock units		161	(161)
Stock-based compensation		1,014				1,014
Stock issued in acquisition of Banc Ed, net of stock issuance costs	$ 7	166,274				166,281
Stock issued in acquisition of Banc Ed, net of stock issuance costs (in shares)	6,725,152
Ending balance at Mar. 31, 2019	$ 56	1,247,340	(57,125)	1,595	(5,725)	1,186,141
Ending Balance (in shares) at Mar. 31, 2019	55,624,627
Increase (decrease) in shareholders' equity
Cumulative change in accounting principal			(15,922)			(15,922)
Beginning balance at Dec. 31, 2019	$ 56	1,248,216	(14,813)	14,960	(27,985)	1,220,434
Beginning Balance (in shares) at Dec. 31, 2019	54,788,772
Increase (decrease) in shareholders' equity
Net income			15,364			15,364
Other comprehensive income (loss)				18,141		18,141
Repurchase of stock					(9,672)	(9,672)
Repurchase of stock (in shares)	(407,850)
Issuance of treasury stock for employee stock purchase plan		(38)			269	231
Issuance of treasury stock for employee stock purchase plan (in shares)	14,236
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax		(179)			104	(75)
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax (in shares)	5,509
Net issuance of treasury stock for stock options exercised, net of shares redeemed and related tax		(10)			10
Net issuance of treasury stock for stock options exercised, net of shares redeemed and related tax (in shares)	541
Cash dividends common stock			(12,055)			(12,055)
Stock dividend equivalents restricted stock units		173	(173)
Stock-based compensation		1,139				1,139
Ending balance at Mar. 31, 2020	$ 56	$ 1,249,301	$ (27,599)	$ 33,101	$ (37,274)	$ 1,217,585
Ending Balance (in shares) at Mar. 31, 2020	54,401,208