CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Total
Balances at Dec. 31, 2012	$ 273	$ 289,711	$ 284,157	$ (57,770)	$ (57,372)	$ 458,999
Balances (in shares) at Dec. 31, 2012	27,296			1,678
Increase (Decrease) in Stockholders' Equity
Net income			15,811			15,811
Other comprehensive income (loss), net of tax					42,460	42,460
Issuance of common stock under share-based compensation plans	$ 2	2,884				2,886
Issuance of common stock under share-based compensation plans (in shares)	211
Tax effect of share-based compensation plans		(1,956)				(1,956)
Share-based compensation expense		5,494				5,494
Dividends declared on common stock			(3,233)			(3,233)
Balances at Dec. 31, 2013	$ 275	296,133	296,735	$ (57,770)	(14,912)	520,461
Balances (in shares) at Dec. 31, 2013	27,507			1,678
Increase (Decrease) in Stockholders' Equity
Net income			46,177			46,177
Other comprehensive income (loss), net of tax					(8,567)	(8,567)
Issuance of common stock under share-based compensation plans	$ 2	1,032				1,034
Issuance of common stock under share-based compensation plans (in shares)	215
Tax effect of share-based compensation plans		(1,118)				(1,118)
Share-based compensation expense		6,998				6,998
Dividends declared on common stock			(4,102)			(4,102)
Balances at Dec. 31, 2014	$ 277	303,045	338,810	$ (57,770)	(23,479)	560,883
Balances (in shares) at Dec. 31, 2014	27,722			1,678
Increase (Decrease) in Stockholders' Equity
Net income			44,854			44,854
Other comprehensive income (loss), net of tax					(4,017)	(4,017)
Issuance of common stock under share-based compensation plans	$ 2	(2)
Issuance of common stock under share-based compensation plans (in shares)	216
Tax effect of share-based compensation plans		(1,419)				(1,419)
Share-based compensation expense		8,029				8,029
Dividends declared on common stock			(6,837)			(6,837)
Purchase of treasury stock				$ (12,765)		(12,765)
Purchase of treasury stock (in shares)				402
Balances at Dec. 31, 2015	$ 279	$ 309,653	$ 376,827	$ (70,535)	$ (27,496)	$ 588,728
Balances (in shares) at Dec. 31, 2015	27,938			2,080