Consolidated Statement of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2011	$ 523,643	$ 997	$ 216,426	$ 721,281	$ (366,954)	$ (48,107)
Balance (in shares) at Dec. 31, 2011		99,701
Increase (Decrease) in Stockholders' Equity
Net income	97,631			97,631
Recognition of share-based compensation	37,146		37,146
Issuance of nonvested shares			(31,112)		31,112
Dividends accrued, $0.75 per share	(64,464)			(64,464)
Excess tax benefits from share-based payment arrangements	3,298		3,298
Repurchase of common stock	(36,004)				(36,004)
Unrealized appreciation of available for sale investment securities	4,987					4,987
Valuation allowance on investment securities' deferred tax asset	1,755					1,755
Pension and postretirement benefits	2,364					2,364
Reclassification adjustment for amounts included in net income	(2,001)					(2,001)
Balance at Sep. 30, 2012	$ 568,355	$ 997	$ 225,758	$ 754,448	$ (371,846)	$ (41,002)
Balance (in shares) at Sep. 30, 2012		99,701