Accounts Payable and Accrued Liabilities - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Accounts Payable And Accrued Liabilities [Line Items]
Outstanding checks	$ 29,300,000		$ 52,600,000
Change in contingent considerations	9,700,000	$ 56,100,000
Permian Acquisition [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Fair value of first potential earn-out payment	0
Change in contingent considerations	$ 9,700,000	$ 56,000,000