Condensed Consolidated Statements of Stockholders' Equity (USD $) In Thousands		Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings
Beginning Balance at Dec. 31, 2012		$ 1,036,860	$ 435	$ 747,868	$ (13,855)	$ 302,412
Stock issued for benefit plans		1,622		(1,171)	2,793
Stock options exercised		4		4
Purchase of treasury shares		(1,513)			(1,513)
Tax benefits from stock compensation		(1,607)		(1,607)
Employee stock purchase plan		946	1	945
Issuance of restricted stock			3	(3)
Amortization of share-based compensation		15,936		15,936
Net Income		(19,032)				(19,032)
Ending Balance at Dec. 31, 2013		1,033,216	439	761,972	(12,575)	283,380
Stock issued for benefit plans		1,909		(1,876)	3,785
Purchase of treasury shares		(896)			(896)
Employee stock purchase plan		824	1	823
Issuance of restricted stock			3	(3)
Amortization of share-based compensation		5,959		5,959
Net Income		13,451				13,451
Ending Balance at Jun. 30, 2014	[1]	$ 1,054,463	$ 443	$ 766,875	$ (9,686)	$ 296,831

[1] (1) Unaudited