Stockholders' Equity - Common and Preferred Shares - Summary of Company's Outstanding Common Stock Warrants (Parenthetical) (Detail) (Private Placement Series B Warrants [Member])	3 Months Ended
	Mar. 31, 2015
Private Placement Series B Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant expiration date	Apr. 16, 2015