Issuance of Notes Payable and Warrants - Additional Information (Detail) (USD $)				12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Class A [Member]	Dec. 31, 2012 Class A [Member]	Dec. 31, 2013 Class A [Member] Maximum [Member]	Aug. 21, 2008 Senior Notes [Member]	Dec. 31, 2013 Senior Notes [Member]	Aug. 21, 2008 Warrant [Member] Class A [Member]
Issuance Of Notes Payable And Warrants [Line Items]
Principal amount of senior notes	$ 120,000,000				$ 120,000,000
Principal Amount Of Senior Notes Due Year					2020
Senior Notes coupon interest (as a percent)					5.20%
Warrants to purchase Class A shares (in shares)							5,455,000
Class A Common stock par value (in dollars per share)		$ 0.01	$ 0.01				$ 0.01
Class A Shares purchase price per share (in dollars per share)							$ 22.00
Senior notes effective yield (as a percent)						7.94%
Redemption period (in days)						90 days
Event of default under the indenture accreted amount due and payable (as a percent)						33.33%
Maximum percent of aggregate principal amount of senior notes owned by holder or group of affiliates for transfer (as a percent)						15.00%
Maximum percent of voting securities and total shares of class A common stock owned by holder or group of affiliates for warrant transfer (as a percent)		2.00%
Percent of outstanding shares of common stock owned by holder or group of affiliates for warrant transfer (as a percent)				25.00%