CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common stock	Additional paid-in capital	Unearned compensation	Retained earnings	Accumulated other comprehensive loss	Treasury stock	Comprehensive income
Balance at Dec. 31, 2011	$ 553,365	$ 229	$ 494,304	$ (2,790)	$ 109,477	$ (4,885)	$ (42,970)
Balance (in shares) at Dec. 31, 2011		21,148
Comprehensive income:
Net income	5,844				5,844			5,844
Other comprehensive income	993					993		993
Total comprehensive income	6,837							6,837
Cash dividends declared $0.18 and $0.17 for the period ended March 31, 2013 and 2012, respectively	(3,603)				(3,603)
Forfeited shares			11	119			(130)
Forfeited shares (in shares)		(6)
Exercise of stock options	16				(6)		22
Exercise of stock options (in shares)		1
Restricted stock grants			(134)	(1,380)			1,514
Restricted stock grants (in shares)		60
Stock-based compensation	466			466
Net tax benefit related to stock-based compensation	18		18
Other, net	(265)						(265)
Other, net (in shares)		(11)
Balance at Mar. 31, 2012	556,834	229	494,199	(3,585)	111,712	(3,892)	(41,829)
Balance (in shares) at Mar. 31, 2012		21,192
Balance at Dec. 31, 2012	667,265	265	585,360	(3,035)	122,014	(2,979)	(34,360)
Balance (in shares) at Dec. 31, 2012		25,148
Comprehensive income:
Net income	10,465				10,465			10,465
Other comprehensive income	1,308					1,308		1,308
Total comprehensive income	11,773							11,773
Cash dividends declared $0.18 and $0.17 for the period ended March 31, 2013 and 2012, respectively	(4,561)				(4,561)
Treasury stock purchased	(2,434)						(2,434)
Treasury stock purchased (in shares)		(98)
Forfeited shares			8	90			(98)
Forfeited shares (in shares)		(4)
Exercise of stock options	1,827				(1,488)		3,315
Exercise of stock options (in shares)		118
Restricted stock grants			(691)	(3,485)			4,176
Restricted stock grants (in shares)		146
Stock-based compensation	881		296	585
Net tax benefit related to stock-based compensation	479		479
Other, net	(1,348)						(1,348)
Other, net (in shares)		(56)
Balance at Mar. 31, 2013	$ 673,882	$ 265	$ 585,452	$ (5,845)	$ 126,430	$ (1,671)	$ (30,749)
Balance (in shares) at Mar. 31, 2013		25,254