Commitments and Contingencies (Operating Lease Payments) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating Leased Assets [Line Items]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 23,900	$ 13,300
Operating Lease, Weighted Average Discount Rate, Percent	3.70%		4.70%
Operating Lease, Weighted Average Remaining Lease Term	4 years 7 months 6 days		4 years 7 months 6 days
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2017	$ 8,652
Total minimum lease payments	54,984
lessee, operating lease, interest due	(4,506)
Operating Lease, Liability, Current	14,902		$ 12,857
Operating Lease, Liability, Noncurrent	40,082		$ 30,334
Operating Lease, Payments	8,300	$ 10,400
Property Subject to Operating Lease [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2018	14,793
2019	10,864
2020	9,610
2021	8,394
2022 and beyond	7,177
Lessee, Operating Lease, Liability, Payments, Due	$ 59,490