Segment and Geographic Information (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,250	$ 1,194	$ 1,250	$ 1,181	$ 1,226	$ 1,116	$ 1,072	$ 1,035	$ 4,875	$ 4,450	$ 3,954
Long-lived Assets	2,754				2,944				2,754	2,944
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									2,892	2,684	2,373
Long-lived Assets	2,209				2,376				2,209	2,376
European region [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									1,227	1,067	951
Long-lived Assets	432				441				432	441
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									483	454	423
Long-lived Assets	59				70				59	70
Rest of the world [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									273	245	207
Long-lived Assets	$ 54				$ 57				$ 54	$ 57
Geographic Concentration Risk [Member] | Revenue [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									100.00%	100.00%	100.00%
Geographic Concentration Risk [Member] | Revenue [Member] | United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									59.00%	60.00%	60.00%
Geographic Concentration Risk [Member] | Revenue [Member] | European region [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									25.00%	24.00%	24.00%
Geographic Concentration Risk [Member] | Revenue [Member] | Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									10.00%	10.00%	11.00%
Geographic Concentration Risk [Member] | Revenue [Member] | Rest of the world [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									6.00%	6.00%	5.00%
Geographic Concentration Risk [Member] | Long-lived Assets [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									100.00%	100.00%
Geographic Concentration Risk [Member] | Long-lived Assets [Member] | United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									80.00%	81.00%
Geographic Concentration Risk [Member] | Long-lived Assets [Member] | European region [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									16.00%	15.00%
Geographic Concentration Risk [Member] | Long-lived Assets [Member] | Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									2.00%	2.00%
Geographic Concentration Risk [Member] | Long-lived Assets [Member] | Rest of the world [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Concentration risk									2.00%	2.00%