Commitments and Contingencies - Summary of Company's Exit Liability Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Beginning balance	$ 779	$ 2,085
Change in estimated loss from exit	1,120	525	$ 3,804
Non-cash adjustment			1,120
Amortization of liability	(1,052)	(1,831)	(2,839)
Ending balance	$ 847	$ 779	$ 2,085