Debt (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Nov. 30, 2015	Oct. 31, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Interest expense				$ 218	$ 122	$ 401	$ 237
Secured Loan Arrangement
Debt Instrument [Line Items]
Exercise price of warrants (in dollars per share)				$ 2.3229		$ 2.3229
Line Of Credit-UBS
Debt Instrument [Line Items]
Borrowing capacity									$ 50,000
Borrowings	$ 8,000	$ 10,000	$ 32,000
Repayments	$ 1,000
Outstanding balance		$ 42,000		$ 50,000		$ 50,000		$ 49,000
Accrued interest						$ 200		$ 600
Line Of Credit-UBS | 30-day LIBOR
Debt Instrument [Line Items]
Spread on variable rate (as a percent)						0.65%