v3.5.0.2
Investment Components, Including Associated Derivatives but Excluding Held to Maturity Investments (Detail) - USD ($)
$ in Millions
Sep. 30, 2016
Jun. 30, 2016
Sep. 30, 2015
Jun. 30, 2015
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis $ 142,669 $ 119,053    
Unrealized Gains 4,955 4,895    
Unrealized Losses (232) (302)    
Recorded Basis 147,392 123,646    
Cash and cash equivalents 13,928 6,510 $ 5,431 $ 5,595
Short-term Investments 123,004 106,730    
Equity and Other Investments 10,460 10,406    
Cash        
Cash, Cash Equivalents and Investments [Line Items]        
Cash 3,473 3,501    
Unrealized Gains 0 0    
Unrealized Losses 0 0    
Cash 3,473 3,501    
Cash and cash equivalents 3,473 3,501    
Short-term Investments 0 0    
Equity and Other Investments 0 0    
Mutual funds        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 1,516 1,012    
Unrealized Gains 0 0    
Unrealized Losses 0 0    
Recorded Basis 1,516 1,012    
Cash and cash equivalents 1,516 1,012    
Short-term Investments 0 0    
Equity and Other Investments 0 0    
Commercial paper        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 745 298    
Unrealized Gains 0 0    
Unrealized Losses 0 0    
Recorded Basis 745 298    
Cash and cash equivalents 645 298    
Short-term Investments 100 0    
Equity and Other Investments 0 0    
Certificates of deposit        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 1,304 1,000    
Unrealized Gains 0 0    
Unrealized Losses 0 0    
Recorded Basis 1,304 1,000    
Cash and cash equivalents 1,128 868    
Short-term Investments 176 132    
Equity and Other Investments 0 0    
U.S. government and agency securities        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 112,619 89,970    
Unrealized Gains 116 245    
Unrealized Losses (34) (11)    
Recorded Basis 112,701 90,204    
Cash and cash equivalents 6,916 100    
Short-term Investments 105,785 90,104    
Equity and Other Investments 0 0    
Foreign government bonds        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 5,709 5,502    
Unrealized Gains 9 10    
Unrealized Losses (18) (18)    
Recorded Basis 5,700 5,494    
Cash and cash equivalents 250 731    
Short-term Investments 5,450 4,763    
Equity and Other Investments 0 0    
Mortgage- and asset-backed securities        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 4,599 4,789    
Unrealized Gains 24 21    
Unrealized Losses (1) (2)    
Recorded Basis 4,622 4,808    
Cash and cash equivalents 0 0    
Short-term Investments 4,622 4,808    
Equity and Other Investments 0 0    
Corporate notes and bonds        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 6,440 6,509    
Unrealized Gains 108 110    
Unrealized Losses (18) (35)    
Recorded Basis 6,530 6,584    
Cash and cash equivalents 0 0    
Short-term Investments 6,530 6,584    
Equity and Other Investments 0 0    
Municipal securities        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 284 285    
Unrealized Gains 59 57    
Unrealized Losses 0 0    
Recorded Basis 343 342    
Cash and cash equivalents 0 0    
Short-term Investments 343 342    
Equity and Other Investments 0 0    
Common and preferred stock        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 5,395 5,597    
Unrealized Gains 4,639 4,452    
Unrealized Losses (161) (236)    
Recorded Basis 9,873 9,813    
Cash and cash equivalents 0 0    
Short-term Investments 0 0    
Equity and Other Investments 9,873 9,813    
Other investments        
Cash, Cash Equivalents and Investments [Line Items]        
Cost Basis 585 590    
Unrealized Gains 0 0    
Unrealized Losses 0 0    
Recorded Basis 585 590    
Cash and cash equivalents 0 0    
Short-term Investments (2) (3)    
Equity and Other Investments $ 587 $ 593