v3.3.1.900
Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance $ 27,485 $ 26,616 $ 25,585
Other comprehensive income (loss) (175) (238) 24
Balance 28,580 27,485 26,616
Unrealized Gains (Losses) on Available-for-Sale Investments [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance 2 7 16
Other comprehensive income (loss) before reclassifications (1) 3 4
Amount reclassified from AOCI (2) (8) (13)
Other comprehensive income (loss) (3) (5) (9)
Balance (1) 2 7
Benefit Plans [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance 4 6 (4)
Other comprehensive income (loss) before reclassifications 1 (2) 10
Amount reclassified from AOCI 0 0 0
Other comprehensive income (loss) 1 (2) 10
Balance 5 4 6
Foreign Currency Translation Adjustments [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance (279) (48) (71)
Other comprehensive income (loss) before reclassifications (173) (231) 23
Amount reclassified from AOCI 0 0 0
Other comprehensive income (loss) (173) (231) 23
Balance (452) (279) (48)
Accumulated Other Comprehensive Income (Loss) [Member]      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Balance (273) (35) (59)
Other comprehensive income (loss) before reclassifications (173) (230) 37
Amount reclassified from AOCI (2) (8) (13)
Other comprehensive income (loss) (175) (238) 24
Balance $ (448) $ (273) $ (35)