Leases Costs and Supplemental Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating lease expense	$ 4,796	$ 9,486
Variable lease expense	761	1,370
Sublease income	(168)	(371)
Total lease expense	5,389	10,485
ROU assets	104,046	104,046
Lease liabilities	$ 110,987	$ 110,987
Weighted-average remaining lease term	8 years 4 months 24 days	8 years 4 months 24 days
Weighted-average discount rate	3.06%	3.06%
Cash paid for amounts included in the measurement of lease liabilities		$ 9,269
ROU assets obtained in exchange for lease obligations		$ 111,995