Leases - Right-of-use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Leases [Abstract]
Right-of-use assets	$ 98,723	$ 94,200
Lease liabilities	$ 119,463	$ 118,900
Weighted average remaining lease term	7 years 10 months 24 days
Weighted average discount rate	3.30%