Condensed Consolidated Statements of Stockholders' Equity (USD $) In Thousands	Total	COMMON STOCK:	CAPITAL SURPLUS:	ACCUMULATED OTHER COMPREHENSIVE INCOME:	RETAINED EARNINGS:
Balance at beginning of period at Dec. 31, 2013		$ 137	$ 868,120	$ 38,071	$ 13,315
Balance at beginning of period, (in shares) at Dec. 31, 2013		137,466
Net issuances of restricted stock, (in shares)		747
Repurchases of common stock, (in shares)		(1,064)
Exercises of stock options, (in shares)		324
Net issuances of restricted stock		1	(1)
Repurchases of common stock		(1)			(43,290)
Exercise of stock options			8,676
Cash dividends					(24,739)
Stock-based compensation expense			8,774
Tax impact of equity incentive plans			1,127
Foreign currency translation adjustments, net of tax	405			405
Net income	61,551				61,551
Balance at end of period at Mar. 31, 2014		137	886,696	38,476	6,837
Balance at end of period, (in shares) at Mar. 31, 2014		137,473
Balance at beginning of period at Dec. 31, 2014	979,858	135	928,157	14,730	36,836
Balance at beginning of period, (in shares) at Dec. 31, 2014		135,134
Net issuances of restricted stock, (in shares)		570
Repurchases of common stock, (in shares)		(672)
Exercises of stock options, (in shares)		40
Net issuances of restricted stock		1	(1)
Repurchases of common stock		(1)			(40,351)
Exercise of stock options			1,113
Cash dividends					(27,048)
Stock-based compensation expense			8,843
Tax impact of equity incentive plans			4,249
Foreign currency translation adjustments, net of tax	(19,962)			(19,962)
Net income	77,922				77,922
Balance at end of period at Mar. 31, 2015	$ 984,623	$ 135	$ 942,361	$ (5,232)	$ 47,359
Balance at end of period, (in shares) at Mar. 31, 2015		135,072