Leases - Lease Cost (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Amortization of lease assets	$ 746	$ 1,571
Interest on lease liabilities	38	68
Operating lease cost	$ 5,432	11,103
Finance Leases, Operating cash outflows		68
Operating Leases, Operating cash outflows		13,334
Finance Leases, Financing cash outflows		1,603
Right-of-use assets obtained in exchange for lease liabilities, Finance leases		3,008
Right-of-use assets obtained in exchange for lease liabilities, Operating leases		$ 2,115
Finance Lease, Weighted average remaining lease term (years)	3 years 1 month 6 days	3 years 1 month 6 days
Operating Lease, Weighted average remaining lease term (years)	8 years 5 months 12 days	8 years 5 months 12 days
Finance Leases, Weighted average discount rate	3.70%	3.70%
Operating Leases, Weighted average discount rate	6.50%	6.50%
Selling, General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 5,396	$ 11,031
Cost of Services
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 36	$ 72