Stockholders' Equity - Additional information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Feb. 28, 2015 USD ($) Executives	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2014 shares	Dec. 31, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of options granted period			10 years
Vesting period of shares			3 years
Unrecognized compensation cost related to non-vested share-based compensation awards granted | $		$ 36,700	$ 36,700
Unrecognized compensation cost related to non-vested share-based compensation awards granted year			2018
Stock option exercisable		2,612,446	2,612,446
Warrants outstanding		3,278,427	3,278,427		3,196,100
Securities excluded from computation of diluted earnings per share			9,500,000	9,700,000
Number of executive officers from whom swing profits were recovered | Executives	1
Short swing profits recovered | $	$ 6
Fair market value of RSUs granted | $			$ 30,800
Vesting period of options			3 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period		0	2,100,000
Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants outstanding		284	284
Weighted average exercise price | $ / shares		$ 3.12	$ 3.12
Directors and Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period			271,614
Fair market value of shares granted | $			$ 1,800