Condensed Consolidated Statements of Shareholders' Equity (unaudited) $ in Thousands	USD ($)
Balance at beginning of period at Dec. 31, 2014	$ 250,371
Balance at beginning of period, as adjusted at Dec. 31, 2014	250,371
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,447
Cash dividends declared	(4,118)
Issuance of common stock	103
Share based compensation	1,153
Share based compensation withholding obligation	(1,091)
Repurchase of common stock	(9,025)
Net change in accumulated other comprehensive loss, net of related tax effect	1,140
Balance at end of period at Sep. 30, 2015	252,980
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,047
Net change in accumulated other comprehensive loss, net of related tax effect	894
Balance at end of period at Sep. 30, 2015	252,980
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	0
Balance at beginning of period at Dec. 31, 2015	251,092
Balance at beginning of period, as adjusted at Dec. 31, 2015	252,339
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,911
Cash dividends declared	(5,149)
Issuance of common stock	61
Share based compensation	1,200
Share based compensation withholding obligation	(627)
Repurchase of common stock	(16,854)
Net change in accumulated other comprehensive loss, net of related tax effect	3,021
Balance at end of period at Sep. 30, 2016	250,902
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,373
Net change in accumulated other comprehensive loss, net of related tax effect	268
Balance at end of period at Sep. 30, 2016	250,902
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	$ 1,247