Leases Supplemental Cash Flow Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating cash flows	$ 5,361
Right-of-use assets obtained in exchange for lease obligations (in millions)	$ 298
Weighted average remaining lease term (in years)	4 years 7 months 9 days
Weighted average discount rate	3.30%