Exit and Termination Costs - Summary of Exit and Termination Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost And Reserve [Line Items]
Severance costs	$ 509	$ 1,595
Total termination costs	13,714	1,595
Pennsylvania
Restructuring Cost And Reserve [Line Items]
Exit cost	210	0
North Louisiana Contract Release
Restructuring Cost And Reserve [Line Items]
Exit cost	$ 12,995	$ 0