Leases - Supplemental Operating Lease Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 1,418	$ 15,997
Operating Lease, Weighted Average Remaining Lease Term	9 years	9 years
Operating Lease, Weighted Average Discount Rate, Percent	5.57%	5.57%