Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended
	Jun. 30, 2009	Mar. 31, 2015	Sep. 16, 2011	Dec. 31, 2014
Class of Stock [Line Items]
Total stock dividend authorized to issue		1,450,644,871
Number of classes of stock		4
Par value of Preferred stock shares			$ 0.01
2009 warrants
Class of Stock [Line Items]
Warrants issued	1,300,000
Exercisable price of warrants to purchase common stock	$ 1.17
Warrants outstanding		400,000
Company Warrants
Class of Stock [Line Items]
Warrants outstanding		1,100,000
Company Warrants were converted into shares of Class A common stock since issuance		300,000
Equity Investment
Class of Stock [Line Items]
Warrants outstanding		7,800,000	7,800,000
Crestview Warrants
Class of Stock [Line Items]
Exercisable price of warrants to purchase common stock			$ 4.34
Class A common stock
Class of Stock [Line Items]
Common stock, shares authorized		750,000,000		750,000,000
Number of votes per share		1
Common stock, shares issued		255,280,514		254,997,925
Class A common stock | Citadel Acquisition
Class of Stock [Line Items]
Common stock, shares issued			71,700,000
Class A common stock | Minimum
Class of Stock [Line Items]
Class A common stock following conversion		4.99%
Class B common stock
Class of Stock [Line Items]
Common stock, shares authorized		600,000,000
Shares of common stock converted		15,400,000
Class C common stock
Class of Stock [Line Items]
Common stock, shares authorized		644,871		644,871
Number of votes per share		10
Common stock, shares issued		644,871		644,871
Series A Redeemable Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized		100,000,000
Par value of Preferred stock shares		0.01