Consolidated Statement Of Changes In Stockholders' Equity (USD $) In Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2012	$ 78,924	$ 6	$ 84,308	$ (5,390)
Beginning Balance (in shares) at Dec. 31, 2012		64,628
Net income	9,957			9,957
Restricted stock vestings (in shares)		221
Restricted stock vestings	83		83
Dividend equivalents cancelled upon forfeiture of performance-based restricted stock awards	50		50
Shares surrendered and cancelled upon vesting of restricted stock to satisfy tax withholdings (in shares)		(79)
Shares surrendered and cancelled upon vesting of restricted stock to satisfy tax withholdings	(1,337)		(1,337)
Stock-based compensation	878		878
Tax deductions relating to stock-based compensation	581		581
Shares issuable in lieu of dividend payments on unvested performance-based restricted stock awards	(133)		(133)
Issuance of common stock under employee stock purchase plan (in shares)		88
Issuance of common stock under employee stock purchase plan	904		904
Ending Balance at Mar. 31, 2013	$ 89,907	$ 6	$ 85,334	$ 4,567
Ending Balance (in shares) at Mar. 31, 2013		64,858