Lease Obligations (Operating Leases) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Lease Term in Excess of One Year [Member]
Operating Leased Assets [Line Items]
Operating leases, rent expense (in dollars)	$ 24.3	$ 19.3	$ 48.9	$ 39.4
Lease Term in Excess of One Year [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year	1 year	1 year	1 year
Lease Term of One Year or Less [Member]
Operating Leased Assets [Line Items]
Operating leases, rent expense (in dollars)	$ 70.7	$ 54.2	$ 117.2	$ 97.1
Lease Term of One Year or Less [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Operating leases, term of contract (in years)	1 year	1 year	1 year	1 year