Leases - Schedule of Lease Cost (Details) - USD ($)	3 Months Ended	6 Months Ended
	Mar. 31, 2019	Jun. 30, 2019
Leases [Abstract]
Short-term lease cost	$ 6,200,000	$ 8,700,000
Operating lease cost	1,600,000	3,100,000
Total lease cost	7,800,000	11,800,000
Cash paid for amounts included in the measurement of lease liabilities	1,300,000	2,300,000
ROUAs obtained in exchange for lease obligations	$ 0.7	$ 1.5
Weighted average remaining lease term		7 years
Weighted average discount rate		3.90%