Acquisition Accounting Purchase Price Allocation (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Apr. 30, 2013 Super Media, Inc.
Fair value of assets acquired
Cash and cash equivalents			$ 154
Accounts receivable			104
Unbilled accounts receivable			316
Other current assets			64
Fixed assets and capitalized software			42
Intangible assets			635
Goodwill	396	0	396
Pension assets			58
Other non-current assets			4
Total fair value of assets acquired			1,773
Fair value of liabilities acquired
Accounts payable and accrued liabilities			114
Long-term debt (including current maturities)			1,082
Employee benefit obligations			99
Unrecognized tax benefits			45
Deferred tax liabilities			351
Total fair value of liabilities acquired			1,691
Total allocable purchase price			$ 82