Contract Costs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue
Contract costs, net	$ 42,927,000	$ 39,020,000
Capitalized contract, term	38 months
Amortization of contract costs	$ 23,330,000	14,939,000	$ 0
Impairment loss in relation to costs capitalized	0	0
Sales commissions
Disaggregation of Revenue
Contract costs, net	4,800,000	4,200,000
Amortization of contract costs	2,600,000	1,500,000
Freight and mobilization
Disaggregation of Revenue
Contract costs, net	38,100,000	34,800,000
Amortization of contract costs	$ 20,700,000	$ 13,400,000