Lease Obligations (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Capital Leases [Line Items]
Assets held under capital lease, net	$ 102,200,000	$ 27,700,000
Machinery and Equipment [Member]
Capital Leases [Line Items]
Conversion of leases from operating to capital	0	23,366,000	0
Segment, Continuing Operations [Member]
Capital Leases [Line Items]
Operating leases, rent expense	$ 222,500,000	$ 168,800,000	$ 129,300,000