CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (loss)	Treasury Stock	Total
Balance at Dec. 31, 2016	$ 39	$ 781,716	$ (163,689)	$ 36	$ (23,788)	$ 594,314
Increase (decrease) in shareholders' equity
Net income			31,649			31,649
Other comprehensive income (loss)				269		269
Issuance of treasury stock for employee stock purchase plan		(361)			664	303
Net issuance of treasury stock for restricted stock unit vesting and related tax benefit		(969)			914	(55)
Net issuance of stock options exercised, net of shares redeemed		(784)			921	137
Cash dividends common stock at $0.40 and $0.36 per share for six months ended June 30, 2018 and 2017 respectively			(13,764)			(13,764)
Stock dividend equivalents restricted stock units at $0.40 and $0.36 per share for six months ended June 30, 2018 and 2017 respectively		181	(181)
Stock dividend accrued on restricted stock awards assumed with the Pulaski Financial Corp. acquisition at $0.36 per share for six months ended June 30, 2018 and 2017 respectively			(11)			(11)
Return of 28,648 equity trust shares					(860)	(860)
Stock-based compensation		1,133				1,133
Balance at Jun. 30, 2017	39	780,916	(145,996)	305	(22,149)	613,115
Balance at Dec. 31, 2017	49	1,084,889	(132,122)	(2,810)	(15,003)	935,003
Increase (decrease) in shareholders' equity
Net income			46,779			46,779
Other comprehensive income (loss)				(7,450)		(7,450)
Tax Cuts and Jobs Act ("TCJA") of 2017 reclassification			605	(605)
Issuance of treasury stock for employee stock purchase plan		(328)			666	338
Net issuance of treasury stock for restricted stock unit vesting and related tax benefit		(1,875)			1,803	(72)
Net issuance of stock options exercised, net of shares redeemed		(2,367)			2,713	346
Cash dividends common stock at $0.40 and $0.36 per share for six months ended June 30, 2018 and 2017 respectively			(19,482)			(19,482)
Stock dividend equivalents restricted stock units at $0.40 and $0.36 per share for six months ended June 30, 2018 and 2017 respectively		282	(284)			(2)
Stock-based compensation		1,722				1,722
Balance at Jun. 30, 2018	$ 49	$ 1,082,323	$ (104,504)	$ (10,865)	$ (9,821)	$ 957,182