Assets and Liabilities Measured at Fair Value on Recurring Basis (Parenthetical) (Detail) In Millions, unless otherwise specified	Sep. 30, 2013 USD ($)	Jun. 30, 2013 USD ($)	Sep. 30, 2013 Gross USD ($)	Jun. 30, 2013 Gross USD ($)	Sep. 30, 2013 Level 3 Gross USD ($)		Jun. 30, 2013 Level 3 Gross USD ($)	Sep. 30, 2013 Corporate notes and bonds Gross USD ($)	Jun. 30, 2013 Corporate notes and bonds Gross USD ($)	Sep. 30, 2013 Corporate notes and bonds Level 3 Gross USD ($)		Jun. 30, 2013 Corporate notes and bonds Level 3 Gross USD ($)	Sep. 30, 2013 Nokia Corporate notes and bonds Level 3 Gross EUR (€)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 88,603	$ 84,468	$ 88,700	$ 84,549	$ 2,089	[1]	$ 24	$ 7,127	$ 4,934	$ 2,048	[1]	$ 19	€ 1,500

[1] Level 3 assets at September 30, 2013 primarily comprised €1.5 billion principal amount of Nokia convertible notes. The valuation of these notes considers the probability of the acquisition transaction closing as well as an analysis of market comparable transactions and management assumptions. The probability-weighted scenarios are considered significant unobservable inputs used in the fair value measurement of both the convertible notes and the embedded derivative. Significant changes in these probabilities in isolation would significantly alter the fair value measurement for both the notes and the embedded derivative.