Class A Redeemable Convertible Preferred Stock - Schedule of Redemption Discounts (Detail) - Series A Redeemable Convertible Preferred Stock [Member]	12 Months Ended
	Dec. 31, 2015
Commencing on the Original Issue Date and Ending on the 1st Anniversary of Original Issue Date [Member]
Temporary Equity [Line Items]
Redemption Discount	9.0909%
Commencing on the Day After the 1st Anniversary of the Original Issue Date and Ending on the 2nd Anniversary of the Original Issue Date [Member]
Temporary Equity [Line Items]
Redemption Discount	6.8182%
Commencing on the Day After the 2nd Anniversary of the Original Issue Date and Ending on the 3rd Anniversary of the Original Issue Date [Member]
Temporary Equity [Line Items]
Redemption Discount	4.5455%
Commencing on the Day After the 3rd Anniversary of the Original Issue Date and Ending on the 4th Anniversary of the Original Issue Date [Member]
Temporary Equity [Line Items]
Redemption Discount	2.2727%