Financial Instruments and Fair Value Measures (Details 6) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Assets
Investments	$ 37	$ 145
Total assets	37	145
Liabilities
Short-term borrowings	406	425
Current portion of long-term debt and lease obligations	2,016	4,026
Long-term debt and lease obligations, excluding fair value hedges	29,143	10,803
Total liabilities	31,565	15,254
Quoted prices in active markets for identical assets (Level 1)
Assets
Investments		68
Total assets		68
Liabilities
Current portion of long-term debt and lease obligations		4,005
Long-term debt and lease obligations, excluding fair value hedges	27,061	10,710
Total liabilities	27,061	14,715
Significant other observable inputs (Level 2)
Assets
Investments		13
Total assets		13
Liabilities
Short-term borrowings	406	425
Current portion of long-term debt and lease obligations	2,016	21
Long-term debt and lease obligations, excluding fair value hedges	2,082	93
Total liabilities	4,504	539
Significant unobservable inputs (Level 3)
Assets
Investments	37	64
Total assets	$ 37	$ 64