Lease Obligations (Operating Leases) (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Lease Term in Excess of One Year [Member]
Operating Leased Assets [Line Items]
Operating leases, rent expense (in dollars)	$ 19.3	$ 17.3	$ 39.4	$ 33.3
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)	$ 54.2	$ 40.4	$ 97.1	$ 88.2
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