Segment Information (Net Revenue By Revenue Composition) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue	$ 1,209	$ 922	$ 711	$ 955	$ 1,368	$ 1,061	$ 715	$ 999	$ 3,797	$ 4,143	$ 3,589
Publishing And Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue									2,255	2,761	2,632
Wireless, Internet-Derived, Advertising (Digital) [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue									1,440	1,159	743
Distribution [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net revenue									$ 102	$ 223	$ 214