Lease Commitments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease rental expense, net	$ 79.0	$ 76.7	$ 76.1
Lower Limit
Lessee, Lease, Description [Line Items]
Lease terms (in years)				9 years
Upper Limit
Lessee, Lease, Description [Line Items]
Lease terms (in years)				15 years