CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2010	$ 607,258	$ 34,131	$ 225,543	$ 374,700	$ (9,340)	$ (17,776)
Balance (in shares) at Dec. 31, 2010		33,318,943
Net income	54,154			54,154
Other comprehensive income, net of tax	32,758				32,758
Dividends declared:
Common, $0.74 per share	(26,428)			(26,428)
Common stock issued under Stock Plan, including tax benefits of $355 (in shares)		156,772
Common stock issued under Stock Plan, including tax benefits of $355	2,273	155	2,073			45
Stock-based compensation	3,038		3,038
Stock issued for acquisition (in shares)		3,352,801
Stock issued for acquisition	82,580	3,353	79,227
Balance at Sep. 30, 2011	$ 755,633	$ 37,639	$ 309,881	$ 402,426	$ 23,418	$ (17,731)
Balance (in shares) at Sep. 30, 2011		36,828,516