Commitments and Contingencies (Operating Lease Payments) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Operating Leased Assets [Line Items]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 26,400	$ 15,700
Operating Lease, Weighted Average Discount Rate, Percent	3.50%		4.70%
Operating Lease, Weighted Average Remaining Lease Term	4 years 4 months 24 days		4 years 7 months 6 days
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2017	$ 4,378
Total minimum lease payments	52,904
lessee, operating lease, interest due	(4,064)
Operating Lease, Liability, Current	14,551		$ 12,857
Operating Lease, Liability, Noncurrent	38,353		$ 30,334
Operating Lease, Payments	12,800	$ 15,500
Property Subject to Operating Lease [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2018	15,277
2019	11,291
2020	9,943
2021	8,776
2022 and beyond	7,303
Lessee, Operating Lease, Liability, Payments, Due	$ 56,968