Leases and Other - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2017 USD ($)
Leases and Other (Textual) [Abstract]
Lease expiration period	40 years
Aggregate purchase obligation	$ 38.1

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

No definition available.