Supplementary Balance Sheet Data (Tables)

9 Months Ended

Sep. 30, 2012

Disclosure Text Block Supplement [Abstract]

Supplementary Balance Sheet Data

(in millions)	September 30, 2012		December 31, 2011		September 30, 2011
Accounts receivable — allowance for doubtful accounts	$	64	$	55	$	64
Accounts receivable — allowance for sales returns	193		187		233
Prepublication costs — accumulated amortization	1,200		1,066		1,038
Property and equipment — accumulated depreciation	1,021		1,066		1,057