Stockholders' Equity - Summary of Activity for Restricted Stock Grants (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested [Roll Forward]
Shares, Nonvested, Beginning Balance	458,981	248,804	131,333
Shares, Granted	215,800	288,648	165,638
Shares, Vested	(97,928)	(72,471)	(43,167)
Shares, Forfeited	(3,500)	(6,000)	(5,000)
Shares, Nonvested, Ending Balance	573,353	458,981	248,804
Weighted Average Grant Date Fair Value, Nonvested, Beginning balance	$ 10.85	$ 8.43	$ 10.58
Weighted Average Grant Date Fair Value, Granted	$ 15.77	$ 12.18	$ 7.22
Weighted Average Grant Date Fair Value, Vested	$ 11.78	$ 7.81	$ 10.47
Weighted Average Grant Date Fair Value, Forfeited	$ 15.66	$ 10.91	$ 7.34
Weighted Average Grant Date Fair Value, Nonvested, Ending balance	$ 12.51	$ 10.85	$ 8.43