Acquisitions (Details) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2013 Invoco Holding GmbH [Member] USD ($)	Mar. 31, 2013 Invoco Holding GmbH [Member] EUR (€)
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition			Jan. 15, 2014	Jan. 15, 2014
Payments to Acquire Businesses, Net of Cash Acquired	$ 54	$ 53	$ 54	€ 40