Leases (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) lease
Lessee, Lease, Description [Line Items]
Number of operating leases	128
Option to extend, operating lease (up to)	15 years
Number of finance leases	4
Number of operating leases not yet commenced	2
Additional leases not yet commenced | $	$ 22.7
Number of direct financing leases	106
Option to extend, direct financing lease (up to)	1 year
Minimum
Lessee, Lease, Description [Line Items]
Option to terminate	4 years
Lease term, not yet commenced	2 years
Maximum
Lessee, Lease, Description [Line Items]
Option to terminate	5 years
Lease term, not yet commenced	3 years