Subsequent Event (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Management Services - North America	Sep. 30, 2013 Debt Due 2014 [Member]		Dec. 31, 2012 Debt Due 2014 [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount						$ 299,570,000		$ 450,000,000
Debt Instrument, Interest Rate, Stated Percentage						4.875%	[1],[2]
Subsequent Event, Disposition of Business, Transaction Costs	314,000,000
Revenues	$ 938,786,000	$ 949,789,000	$ 2,838,214,000	$ 2,899,548,000	$ 7,000,000

[1] Prior to the Tender Offer, we had interest rate swap agreements with an aggregate notional value of $450 million that effectively converted the fixed rate interest payments on these notes into variable interest rates. As a result of the Tender Offer, we unwound $225 million of these swap agreements.

[2] During the first quarter, we completed a cash tender offer (the Tender Offer) for a portion of our 4.875% Notes due 2014, our 5.0% Notes due 2015, and our 4.75% Notes due 2016 (the Subject Notes). Holders who validly tendered their notes received the principal amount of the notes tendered, all accrued and unpaid interest and a premium amount. An aggregate $405 million of the Subject Notes were tendered. We recognized a net loss of $25 million, consisting of the payment of the call premium and transaction fees and the write-off of unamortized costs, partially offset by a gain from the unwinding of interest rate swap agreements as other expense, net on the Condensed Consolidated Statements of Income.