Consolidated Statements of Stockholders' Equity (USD $) In Thousands		Total		Common Stock		Paid-in Capital	Retained Earnings
Balance at Dec. 31, 2010		$ 116,739		$ 149	[1]	$ 0	$ 116,590	[1]
Balance (in shares) at Dec. 31, 2010	[1]			37,137
Net income		13,986					13,986	[1]
Stock options exercised and restricted stock awards granted, including tax benefits (in shares)	[1]			108
Stock options exercised and restricted stock awards granted, including tax benefits		705				705
Share-based compensation		680				680
Stock repurchased and retired (in shares)	[1]			(318)
Stock repurchased and retired		(3,671)		(1)	[1]	(1,375)	(2,295)	[1]
Dividends		(5,935)				(10)	(5,925)	[1]
Balance at Dec. 31, 2011		122,504		148	[1]	0	122,356	[1]
Balance (in shares) at Dec. 31, 2011	[1]			36,927
Net income		27,449					27,449	[1]
Stock options exercised and restricted stock awards granted, including tax benefits (in shares)	[1]			354
Stock options exercised and restricted stock awards granted, including tax benefits		2,389		1	[1]	2,388
Share-based compensation		1,294				1,294
Stock repurchased and retired (in shares)	[1]			(504)
Stock repurchased and retired		(6,660)		(2)	[1]	(3,682)	(2,976)	[1]
Dividends		(8,840)				0	(8,840)	[1]
Balance at Dec. 31, 2012		138,136		147	[1]	0	137,989	[1]
Balance (in shares) at Dec. 31, 2012	[1]			36,777
Net income		37,547					37,547
Stock options exercised and restricted stock awards granted, including tax benefits (in shares)	[1]			290
Stock options exercised and restricted stock awards granted, including tax benefits		2,310		1	[1]	2,309
Share-based compensation		1,763				1,763
Stock repurchased and retired (in shares)	[1]			(356)
Stock repurchased and retired		(8,222)		(1)	[1]	(4,072)	(4,149)	[1]
Dividends		(7,428)	[2]			0	(7,428)	[1],[2]
Balance at Dec. 31, 2013		$ 164,106		$ 147	[1]	$ 0	$ 163,959	[1]
Balance (in shares) at Dec. 31, 2013	[1]			36,711

[1] Reflects three-for-two stock split effective July 2, 2013

[2] Includes cash payment of fractional shares from three-for-two stock split effective July 2, 2013