Consolidated Statements of Shareholders' Equity (USD $) In Thousands	Total	Treasury Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2011		$ (200,106)	$ 45,376	$ 212,311	$ 918,699	$ 274
Beginning Balance (in shares) at Dec. 31, 2011		(15,112)
Dividends, $.062, $.072 and $.072 per share in 2013, 2012 and 2011, respectively					(4,710)
Stock-Based Compensation				6,374
Reissued Shares (in shares)		1,317
Reissued Shares		17,662		1,677
Repurchased Shares (in shares)		(1,237)
Repurchased Shares		(34,131)
Net Earnings	173,043				173,043
Foreign Currency Translation Adjustment						(343)
Ending Balance at Dec. 31, 2012		(216,575)	45,376	220,362	1,087,032	(69)
Ending Balance (in shares) at Dec. 31, 2012		(15,032)
Dividends, $.062, $.072 and $.072 per share in 2013, 2012 and 2011, respectively					(5,479)
Stock-Based Compensation				2,250
Reissued Shares (in shares)		739
Reissued Shares		10,825		570
Repurchased Shares (in shares)		(3,502)
Repurchased Shares		(100,000)		(25,000)
Net Earnings	120,666				120,666
Foreign Currency Translation Adjustment						5
Ending Balance at Dec. 31, 2013	1,139,963	(305,750)	45,376	198,182	1,202,219	(64)
Ending Balance (in shares) at Dec. 31, 2013		(17,795)
Dividends, $.062, $.072 and $.072 per share in 2013, 2012 and 2011, respectively					(6,219)
Share-Based Compensation (in shares)		17
Stock-Based Compensation		300		10,398
Reissued Shares (in shares)		515
Reissued Shares		7,162		(6,290)
Repurchased Shares (in shares)		(1,001)
Repurchased Shares		(25,000)		25,000
Net Earnings	78,233				78,233
Foreign Currency Translation Adjustment						(26)
Ending Balance at Dec. 31, 2014	$ 1,223,521	$ (323,288)	$ 45,376	$ 227,290	$ 1,274,233	$ (90)
Ending Balance (in shares) at Dec. 31, 2014		(18,264)