Condensed Consolidated Statements Of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Common Stock And Additional Paid-In Capital [Member]	Retained Earnings [Member]	Cumulative Translation Adjustment [Member]	Retirement Benefits Adjustments [Member]	Cumulative Unrealized Loss On Derivatives [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2011	$ 490,988	$ 1,142,412	$ 24,194	$ (38,486)	$ (41,177)	$ (64,796)	$ 1,513,135
Net income		52,171					52,171
Other comprehensive income, net of tax:
Cumulative translation adjustment			15,031				15,031
Amortization of retirement obligations				1,123			1,123
Amortization of forward starting swaps					1,221		1,221
Issuance of 997,376 shares of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, net of tax benefit	26,097						26,097
Repurchase of 0.2 million shares of common stock						(10,183)	(10,183)
Unvested shares surrendered for tax withholding						(2,118)	(2,118)
Share-based compensation	4,094						4,094
Balance at Mar. 31, 2012	$ 521,179	$ 1,194,583	$ 39,225	$ (37,363)	$ (39,956)	$ (77,097)	$ 1,600,571