Consolidated Statements Of Shareholders' Equity (USD $) In Thousands	Common Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2008	$ 142,327	$ 251,564	$ 393,891
Balance, shares at Dec. 31, 2008	13,689
Net earnings		16,828	16,828
Issuance of common stock for employee benefit plans, shares	4
Issuance of common stock for employee benefit plans	488		488
Tax windfall from share-based compensation	4		4
Repurchase of common stock, shares	(7)
Repurchase of common stock	(235)		(235)
Restricted stock forfeitures, shares	(2)
Amortization of restricted stock	1,946		1,946
Cash dividends		(6,777)	(6,777)
Restricted dividends		(16)	(16)
Stock option plan expense	893		893
Balance at Dec. 31, 2009	145,423	261,599	407,022
Balance, shares at Dec. 31, 2009	13,684
Net earnings		16,353	16,353
Issuance of common stock for employee benefit plans, shares	19
Issuance of common stock for employee benefit plans	564		564
Issuance of common stock for long-term incentive plan, shares	33
Issuance of common stock for long-term incentive plan	1,302		1,302
Issuance of common stock for acquisition, shares	2,733
Issuance of common stock for acquisition	85,482		85,482
Tax shortfall from share-based compensation	(126)		(126)
Repurchase of common stock, shares	(89)
Repurchase of common stock	(944)		(944)
Grant of restricted stock	191
Amortization of restricted stock	4,154		4,154
Cash dividends		(8,165)	(8,165)
Restricted dividends		(76)	(76)
Stock option plan expense	648		648
Balance at Dec. 31, 2010	236,503	269,711	506,214
Balance, shares at Dec. 31, 2010	16,571
Net earnings		64,355	64,355
Issuance of common stock for convertible note payable, shares	453
Issuance of common stock for convertible note payable	16,669		16,669
Issuance of common stock for employee benefit plans, shares	24
Issuance of common stock for employee benefit plans	725		725
Issuance of common stock for long-term incentive plan, shares	34
Issuance of common stock for long-term incentive plan	1,929		1,929
Tax windfall from share-based compensation	151		151
Repurchase of common stock, shares	(25)
Repurchase of common stock	(1,308)		(1,308)
Restricted stock forfeitures, shares	(1)
Grant of restricted stock	122
Amortization of restricted stock	4,377		4,377
Cash dividends		(10,110)	(10,110)
Restricted dividends		(125)	(125)
Stock option plan expense	1,153		1,153
Balance at Dec. 31, 2011	$ 260,199	$ 323,831	$ 584,030
Balance, shares at Dec. 31, 2011	17,178