Leases - Operating Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Right-of-use assets obtained in exchange for new operating lease obligations	$ 109,597
Right-of-use assets obtained in exchange for new finance lease obligations	0
Operating leases - operating cash flows	4,189
Finance leases - operating cash flows	174
Finance leases - financing cash flows	$ 418
Operating leases, weighted-average remaining lease term (in years)	8 years 3 months 8 days
Finance leases, weighted-average remaining lease term (in years)	3 years 7 months 26 days
Operating leases, weighted-average discount rate (percent)	5.60%
Finance leases, weighted-average discount rate (percent)	4.40%