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	92,271
Other comprehensive income (loss), net	(13,288)				(13,288)
Stock Issued During Period, Value, Treasury Stock Reissued	80,398		27,689			52,709
Equity component of 3.00% Convertible Note issuance, net of deferred tax liability	2,531		2,531
Issuance of common and treasury shares to employee benefit plans, shares		52
Issuance of common and treasury shares to employee benefit plans	536	1	(5,705)			6,240
Tax effect from options exercised and the vesting of restricted shares	1,413		1,413
Stock-based compensation	10,434		10,434
Cash dividends	(11,637)			(11,637)
Ending balance at Sep. 30, 2013	$ 1,022,942	$ 259	$ 369,198	$ 758,498	$ (46,345)	$ (58,668)
Ending balance, shares at Sep. 30, 2013		25,888