Leases Supplemental balance sheet information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease liabilities	$ 121,053
Cash paid for amounts included in the measurement of lease liabilities within operating cash flows	6,900
Right of use assets obtained in exchange for operating lease obligations	$ 17,519
Weighted average remaining lease term	6 years 9 months 14 days
Weighted average discount rate	4.23%
Other current liabilities
Lessee, Lease, Description [Line Items]
Current operating lease liabilities	$ 20,300