CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	[1]	Common Stock	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	[1]	Accumulated Other Comprehensive (Loss) Income (Net of Taxes) Available for Sale Securities	Accumulated Other Comprehensive (Loss) Income (Net of Taxes) Available for Sale Securities Cumulative Effect, Period of Adoption, Adjustment	[1]	Accumulated Other Comprehensive (Loss) Income (Net of Taxes) Cash Flow Hedge
Beginning balance (shares) at Dec. 31, 2018				56,379,066
Beginning balance at Dec. 31, 2018	$ 581,145	$ 0		$ 456,378	$ 129,806	$ (399)		$ (4,935)	$ 399		$ (104)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	36,404				36,404
Other comprehensive income	6,607							6,503			104
Issuance of restricted stock awards (in shares)				321,784
Settled restricted stock units (in shares)				499,707
Shares withheld to pay taxes on stock based compensation (in shares)				(223,044)
Shares withheld to pay taxes on stock based compensation	(2,409)			$ (2,409)
Restricted stock forfeitures (in shares)				(72,041)
Restricted stock forfeitures	(202)			$ (220)	18
Stock based compensation expense	2,431			$ 2,431
Shares repurchased (in shares)				(870,701)
Shares repurchased	(8,791)			$ (8,791)
Cash dividends	(9,813)				(9,813)
Ending balance (shares) at Sep. 30, 2019				56,034,771
Ending balance at Sep. 30, 2019	605,372			$ 447,389	156,016			1,967			0
Beginning balance (shares) at Jun. 30, 2019				55,982,491
Beginning balance at Jun. 30, 2019	597,467			$ 449,825	146,514			1,128
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	12,736				12,736
Other comprehensive income	839							839
Settled restricted stock units (in shares)				377,728
Shares withheld to pay taxes on stock based compensation (in shares)				(178,403)
Shares withheld to pay taxes on stock based compensation	(1,972)			$ (1,972)
Restricted stock forfeitures (in shares)				(36,045)
Restricted stock forfeitures	(81)			$ (89)	8
Stock based compensation expense	786			$ 786
Shares repurchased (in shares)				(111,000)
Shares repurchased	(1,161)			$ (1,161)
Cash dividends	(3,242)				(3,242)
Ending balance (shares) at Sep. 30, 2019				56,034,771
Ending balance at Sep. 30, 2019	605,372			$ 447,389	156,016			1,967			0
Beginning balance (shares) at Dec. 31, 2019				55,999,754
Beginning balance at Dec. 31, 2019	614,464			$ 447,784	165,236			1,444			0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31,211				31,211
Other comprehensive income	5,127							5,127
Issuance of restricted stock awards (in shares)				261,722
Settled restricted stock units (in shares)				94,408
Shares withheld to pay taxes on stock based compensation (in shares)				(64,361)
Shares withheld to pay taxes on stock based compensation	(666)			$ (666)
Restricted stock forfeitures (in shares)				(29,661)
Restricted stock forfeitures	(23)			$ (31)	8
Stock based compensation expense	2,742			$ 2,742
Shares repurchased (in shares)				(3,851,809)
Shares repurchased	(34,714)			$ (34,714)
Cash dividends	(9,308)				(9,308)
Ending balance (shares) at Sep. 30, 2020				52,410,053
Ending balance at Sep. 30, 2020	608,833			$ 415,115	187,147			6,571			0
Beginning balance (shares) at Jun. 30, 2020				52,382,895
Beginning balance at Jun. 30, 2020	596,682			$ 414,264	175,852			6,566
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,317				14,317
Other comprehensive income	5							5
Issuance of restricted stock awards (in shares)				11,604
Settled restricted stock units (in shares)				24,188
Shares withheld to pay taxes on stock based compensation (in shares)				(7,797)
Shares withheld to pay taxes on stock based compensation	(75)			$ (75)
Restricted stock forfeitures (in shares)				(837)
Restricted stock forfeitures	(5)			$ (5)	0
Stock based compensation expense	931			$ 931
Cash dividends	(3,022)				(3,022)
Ending balance (shares) at Sep. 30, 2020				52,410,053
Ending balance at Sep. 30, 2020	$ 608,833			$ 415,115	$ 187,147			$ 6,571			$ 0

[1] Represents the impact of adopting Accounting Standards Update ("ASU") 2016-01. See Note 3 to the unaudited consolidated financial statements for further information.