Leases - Operating Lease Costs (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Obligation with Joint and Several Liability Arrangement [Line Items]
Cash paid for amounts included in the measurement of operating lease liabilities		$ 4,474
Right-of-use assets obtained in exchange for lease liabilities		$ 40,524
Weighted-average remaining lease term-operating leases ( in years )	7 years 1 month 6 days	7 years 1 month 6 days
Weighted-average discount rate-operating leases ( as a percent )	5.29%	5.29%
Selling, General and Administrative Expenses
Obligation with Joint and Several Liability Arrangement [Line Items]
Operating lease cost	$ 2,308	$ 4,547
Short term and variable lease cost	552	1,012
Present value of lease liabilities	$ 2,860	$ 5,559