Quarterly Results of Operations - Summary of Quarterly Results of Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Net revenue	$ 60,093	$ 57,786	$ 56,950	$ 49,087	$ 63,752	$ 58,486	$ 54,491	$ 46,524	$ 223,916	$ 223,253	$ 194,396
Net income (loss) applicable to common stockholders	$ 151,093	$ (21,384)	$ 5,073	$ (957)	$ 7,697	$ 7,233	$ 2,066	$ (3,395)	$ 133,825	$ 13,601	$ (8,200)
Net income (loss) per share, basic	$ 1.72	$ (0.24)	$ 0.06	$ (0.01)					$ 1.53	$ 0.16	$ (0.10)
Net income (loss) per share, basic and diluted					$ 0.09	$ 0.08	$ 0.02	$ (0.04)		$ 0.16
Net income (loss) per share, diluted	$ 1.67	$ (0.24)	$ 0.06	$ (0.01)					$ 1.50	$ 0.16	$ (0.10)