Summary of Significant Accounting Policies - Share-Based Compensation Expense (Details) $ in Thousands	Dec. 31, 2016 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopting ASU 2016-09	$ 0
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopting ASU 2016-09	(783)
Additional Paid-In Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopting ASU 2016-09	783
Accounting Standards Update 2016-09, Forfeiture Rate Component | Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopting ASU 2016-09	(800)
Accounting Standards Update 2016-09, Forfeiture Rate Component | Additional Paid-In Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopting ASU 2016-09	$ 800