Operating Expenses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Salary and service costs	$ 2,434.4	$ 2,418.3
Office and general expenses	510.4	410.9
Operating Expenses	$ 2,944.8	$ 2,829.2

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

No definition available.

Name:	us-gaap_OperatingExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration