Consolidated Statement of Stockholders' Equity (USD $) In Thousands	Total	Common Stock	Additional Paid-in-Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance at Dec. 31, 2012	$ 860,284	$ 258	$ 332,836	$ 677,864	$ (33,057)	$ (117,617)
Beginning balance, shares at Dec. 31, 2012		25,836
Net income	59,506
Other comprehensive income (loss), net	(15,625)				(15,625)
Stock Issued During Period, Value, Treasury Stock Reissued	83,558		28,827			54,731
Equity component of 3.00% Convertible Note issuance, net of deferred tax liability	1,669		1,669
Issuance of common and treasury shares to employee benefit plans, shares		98
Issuance of common and treasury shares to employee benefit plans	534	1	(3,827)			4,360
Tax effect from options exercised and the vesting of restricted shares	1,129		1,129
Stock-based compensation	6,935		6,935
Cash dividends	(7,501)			(7,501)
Ending balance at Jun. 30, 2013	$ 990,489	$ 259	$ 367,569	$ 729,869	$ (48,682)	$ (58,526)
Ending balance, shares at Jun. 30, 2013		25,934