Summary of Significant Accounting Policies - Calculation of Basic and Diluted Earnings (Loss) Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accounting Policies [Abstract]
Net Income (Loss)	$ (67,628)	$ (1,910)	$ (1,083,267)	$ (98,139)
Basic weighted-average common shares outstanding in period (in shares)	211,894,790	210,377,152	211,503,310	210,155,678
Diluted weighted-average common shares outstanding in period (in shares)	211,894,790	210,377,152	211,503,310	210,155,678
Basic net income (loss) per common share (in dollars per share)	$ (0.32)	$ (0.01)	$ (5.12)	$ (0.47)
Diluted net income (loss) per common share (in dollars per share)	$ (0.32)	$ (0.01)	$ (5.12)	$ (0.47)