Earnings Per Share - Anti-dilutive Shares (Details) - $ / shares					1 Months Ended			3 Months Ended				6 Months Ended		12 Months Ended
	Apr. 12, 2017	Apr. 04, 2017	Dec. 22, 2016	May 16, 2013	Apr. 30, 2017	Jan. 31, 2014	Feb. 28, 2013	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2013	Dec. 31, 2016
Earnings Per Share
Number of dilutive potential common shares												81,356,826	21,511,424
Stock options
Earnings Per Share
Stock options granted								314,511		265,000		450,863	280,000
Warrants issued in February, 2013
Earnings Per Share
Number of warrants issued (in shares)							23,637,500
Number of warrants unexercised (in shares)									100		100
Exercise price of warrants (in dollars per share)							$ 0.15
Warrants issued in January, 2014
Earnings Per Share
Number of warrants issued (in shares)						4,000,000
Number of warrants exercised (in shares)					4,000,000			4,000,000
Exercise price of warrants (in dollars per share)					$ 0.65	$ 4.00									$ 0.65
Warrants issued in December 2016
Earnings Per Share
Number of warrants issued (in shares)			10,501,500
Shares of common stock that can be purchased from warrants issued (in shares)	5,250,750
Number of warrants exercised (in shares)	10,501,500
Exercise price of warrants (in dollars per share)	$ 1.50		$ 1.50
Warrants issued in April 2017
Earnings Per Share
Number of warrants issued (in shares)					5,250,750
Number of warrants unexercised (in shares)								0
Exercise price of warrants (in dollars per share)					$ 2.69
Warrants issued with the Amazon.com, Inc transaction agreement
Earnings Per Share
Shares of common stock that can be purchased from warrants issued (in shares)		55,286,696
Number of warrants exercised (in shares)		0
Tranche one of warrants issued with the Amazon.com, Inc transaction agreement
Earnings Per Share
Warrant shares vested (in shares)		5,819,652
Series C redeemable convertible preferred stock.
Earnings Per Share
Stock options granted				10,431
Number of preferred shares that had been converted to common stock														5,200
Series D Redeemable Convertible Preferred Stock
Earnings Per Share
Stock options granted			18,500
Shares of common stock that can be purchased from warrants issued (in shares)															7,381,500
Number of preferred shares that had been converted to common stock												14,800
Number of shares redeemed												3,700
Stock options
Earnings Per Share
Number of dilutive potential common shares												15,016,609	11,752,286
Restricted stock
Earnings Per Share
Number of dilutive potential common shares												248,077	204,444
Warrants
Earnings Per Share
Number of dilutive potential common shares												60,537,546	4,000,100
Preferred stock
Earnings Per Share
Number of dilutive potential common shares												5,554,594	5,554,594