Leases (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Operating Leased Assets [Line Items]
Option to extend the lease, term	up to 5 years
Option to terminate the lease, term	within 1 year
Lease right of use assets	$ 87,811
Lease liabilities	$ 98,659
Weighted average rate	3.47%
Operating lease payments related to extended lease terms	$ 2,300
Lease payments for leases signed, but not yet commenced	$ 3,000
Minimum [Member]
Operating Leased Assets [Line Items]
Remaining terms of leases under operating lease	1 year
Maximum [Member]
Operating Leased Assets [Line Items]
Remaining terms of leases under operating lease	10 years