Leases Lease Cost (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Lease, Cost [Abstract]
Operating Lease, Cost	$ 7,487	$ 14,872
Variable Lease, Cost	1,068	2,321
Sublease Income	(155)	(295)
Lease, Cost	8,400	16,898
Operating Lease, Payments	7,738	15,411
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 6,296	$ 12,934
Operating Lease, Weighted Average Remaining Lease Term	8 years 2 months 12 days	8 years 2 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent	3.44%	3.44%