New Accounting Pronoucements - Additional Information (Narrative) (Details) $ in Millions	Sep. 30, 2018 USD ($) location
New Accounting Pronouncements [Line Items]
Number of locations under operating leases | location	100
Minimum [Member]
New Accounting Pronouncements [Line Items]
Operating Lease, Right-of-Use Asset	$ 170.0
Maximum [Member]
New Accounting Pronouncements [Line Items]
Operating Lease, Right-of-Use Asset	$ 190.0