Summary of Significant Accounting Policies - Basic and Diluted Net (Loss) Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator
Net loss from continuing operations	$ (419,503)	$ (123,716)	$ (126,022)
Denominator
Weighted average common shares outstanding, basic and diluted (shares)	43,078	37,884	27,301
Loss from continuing operations per share, basic and diluted (in usd per share)	$ (9.74)	$ (3.27)	$ (4.62)