Supplementary Balance Sheet Data

6 Months Ended

Jun. 30, 2011

Supplementary Balance Sheet Data [Abstract]

Supplementary Balance Sheet Data

3. Supplementary Balance Sheet Data

	June 30,		December 31,		June 30,
	2011		2010		2010
Accounts receivable — allowance for doubtful accounts	$	70.8	$	78.5	$	70.2
Accounts receivable — allowance for sales returns		145.5		197.3		138.0
Prepublication costs — accumulated amortization		955.3		1,089.3		948.4
Property and equipment — accumulated depreciation		1,113.8		1,064.8		1,023.4