Stockholders' Equity (Detail)	1 Months Ended	3 Months Ended
	Jun. 30, 2009 $ / shares shares	Mar. 31, 2017 vote class $ / shares shares	Dec. 31, 2016 shares	Sep. 16, 2011 $ / shares shares
Class of Stock [Line Items]
Total stock dividend authorized to issue (in shares)		268,830,609
Par value of preferred stock shares (USD per share) | $ / shares				$ 0.01
Number of classes of stock | class		4
2009 warrants
Class of Stock [Line Items]
Warrants issued (in shares)	156,250
Exercisable price of warrants to purchase common stock (USD per share) | $ / shares	$ 1.17
Warrants converted (in shares)		0
Warrants outstanding (in shares)		40,057
Company Warrants
Class of Stock [Line Items]
Warrants outstanding (in shares)		31,955
Company warrants were converted into shares of Class A common stock since issuance (in shares)		0
Equity Investment
Class of Stock [Line Items]
Warrants outstanding (in shares)		1,000,000		1,000,000
Crestview Warrants
Class of Stock [Line Items]
Exercisable price of warrants to purchase common stock (USD per share) | $ / shares				$ 34.56
Series A Redeemable Preferred Stock
Class of Stock [Line Items]
Par value of preferred stock shares (USD per share) | $ / shares		$ 0.01
Preferred stock, shares authorized		100,000,000
Class A common stock
Class of Stock [Line Items]
Common stock, shares authorized		93,750,000	93,750,000
Number of votes per share | vote		1
Common stock, shares issued		32,031,952	32,031,952
Common stock, shares outstanding		29,225,765	29,225,765
Class A common stock | Company Warrants
Class of Stock [Line Items]
Company warrants were converted into shares of Class A common stock since issuance (in shares)		43,192
Class A common stock | Citadel Acquisition
Class of Stock [Line Items]
Common stock, shares issued				9,000,000
Class A common stock | Minimum
Class of Stock [Line Items]
Class A common stock following conversion		4.99%
Class B
Class of Stock [Line Items]
Common stock, shares authorized		75,000,000
Common stock, shares issued		0	0
Common stock, shares outstanding		0	0
Class C common stock
Class of Stock [Line Items]
Common stock, shares authorized		80,609	80,609
Number of votes per share | vote		10
Common stock, shares issued		80,609	80,609
Common stock, shares outstanding		80,609	80,609