Consolidated Statement Of Changes In Stockholders' Equity And Comprehensive Income (USD $) In Thousands, except Share data	Comprehensive Income [Member]	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balances at Jan. 01, 2011		$ 199	$ 540,294	$ 503,689	$ (33,709)	$ (214,683)	$ 795,790
Balance, shares at Jan. 01, 2011		101,659,924				(11,011,494)
Net income	100,390			100,390			100,390
Derivative transactions, net of tax	(39,972)				(39,972)		(39,972)
Amortization of prior service credits, net of tax	(122)				(122)		(122)
Amortization of actuarial loss, net of tax	1,267				1,267		1,267
Comprehensive income	61,563
Adjustment for 3 for 2 stock split (Note 1), shares		50,828,084				(5,375,912)
Adjustment for 3 for 2 stock split (Note 1), value				(39)			(39)
Exercise of stock options			(2,528)			15,249	12,721
Exercise of stock options, shares						788,465	1,150,000
Deferred stock issuance			(1,158)			1,117	(41)
Deferred stock issuance, shares						56,505
Issuance of performance-contingent restricted stock			(4,213)			4,213	0
Issuance of performance-contingent restricted stock, shares						216,050
Amortization of share-based payment compensation			10,427				10,427
Tax benefits related to share based payment awards			2,920				2,920
Performance-contingent restricted stock awards forfeitures and cancellations			959			(959)	0
Performance-contingent restricted stock awards forfeitures and cancellations, shares						(51,630)
Stock repurchases						(26,598)	(26,598)
Stock repurchases, shares						(1,155,103)
Issuance of deferred compensation			(219)			219	0
Issuance of deferred compensation, shares						11,672
Contingent acquisition consideration payments			(5,000)				(5,000)
Dividends paid - $0.433 per common share				(58,770)			(58,770)
Balances at Oct. 08, 2011		$ 199	$ 541,482	$ 545,270	$ (72,536)	$ (221,442)	$ 792,973
Balance, shares at Oct. 08, 2011		152,488,008				(16,521,447)