Leases - Lease Cost (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Amortization of lease assets	$ 736	$ 2,307
Interest on lease liabilities	39	107
Operating lease cost	$ 5,420	16,523
Finance Leases, Operating cash outflows		107
Operating Leases, Operating cash outflows		19,714
Finance Leases, Financing cash outflows		2,306
Right-of-use assets obtained in exchange for lease liabilities, Finance leases		3,537
Right-of-use assets obtained in exchange for lease liabilities, Operating leases		$ 9,587
Finance Lease, Weighted average remaining lease term (years)	2 years 9 months 18 days	2 years 9 months 18 days
Operating Lease, Weighted average remaining lease term (years)	8 years 4 months 24 days	8 years 4 months 24 days
Finance Leases, Weighted average discount rate	3.78%	3.78%
Operating Leases, Weighted average discount rate	6.34%	6.34%
Selling, General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 5,284	$ 16,315
Cost of Services
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 136	$ 208