Cash, Cash Equivalents, and Marketable Securities Available for Sale Securities (Details) - USD ($) | 3 Months Ended | 6 Months Ended | |
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016 | Dec. 31, 2016 |
Schedule of Available-for-sale Securities [Line Items] | | | | | |
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds | $ 1,300,000,000 | $ 0 | $ 2,600,000,000 | $ 69,000,000 | |
Available-for-sale Securities, Gross Realized Gains | 2,000,000 | 0 | 3,000,000 | 1,000,000 | |
Available-for-sale Securities, Gross Realized Losses | 6,000,000 | $ 0 | 8,000,000 | 0 | |
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities | | | 0 | $ 0 | |
Operating Segments [Member] | Automotive | | | | | |
Schedule of Available-for-sale Securities [Line Items] | | | | | |
Available-for-sale Securities, Amortized Cost Basis | 8,928,000,000 | | 8,928,000,000 | | $ 6,533,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax | 6,000,000 | | 6,000,000 | | 3,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax | (18,000,000) | | (18,000,000) | | (27,000,000) |
Available-for-sale Securities | 8,916,000,000 | | 8,916,000,000 | | 6,509,000,000 |
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value | 2,205,000,000 | | 2,205,000,000 | | 1,906,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value | 6,614,000,000 | | 6,614,000,000 | | 4,415,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value | 97,000,000 | | 97,000,000 | | 188,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] | | | | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 5,824,000,000 | | 5,824,000,000 | | 2,872,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | (18,000,000) | | (18,000,000) | | (27,000,000) |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 5,824,000,000 | | 5,824,000,000 | | 2,872,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss | (18,000,000) | | (18,000,000) | | (27,000,000) |
Operating Segments [Member] | Automotive | U.S. government | | | | | |
Schedule of Available-for-sale Securities [Line Items] | | | | | |
Available-for-sale Securities, Amortized Cost Basis | 2,587,000,000 | | 2,587,000,000 | | 3,703,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax | 0 | | 0 | | 2,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax | (7,000,000) | | (7,000,000) | | (14,000,000) |
Available-for-sale Securities | 2,580,000,000 | | 2,580,000,000 | | 3,691,000,000 |
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value | 524,000,000 | | 524,000,000 | | 727,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value | 2,056,000,000 | | 2,056,000,000 | | 2,776,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value | 0 | | 0 | | 188,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] | | | | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 2,580,000,000 | | 2,580,000,000 | | 1,474,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | (7,000,000) | | (7,000,000) | | (14,000,000) |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 2,580,000,000 | | 2,580,000,000 | | 1,474,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss | (7,000,000) | | (7,000,000) | | (14,000,000) |
Operating Segments [Member] | Automotive | U.S. government agencies | | | | | |
Schedule of Available-for-sale Securities [Line Items] | | | | | |
Available-for-sale Securities, Amortized Cost Basis | 1,982,000,000 | | 1,982,000,000 | | 308,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax | 1,000,000 | | 1,000,000 | | 0 |
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax | (4,000,000) | | (4,000,000) | | (2,000,000) |
Available-for-sale Securities | 1,979,000,000 | | 1,979,000,000 | | 306,000,000 |
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value | 677,000,000 | | 677,000,000 | | 0 |
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value | 1,237,000,000 | | 1,237,000,000 | | 306,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value | 65,000,000 | | 65,000,000 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] | | | | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 1,172,000,000 | | 1,172,000,000 | | 261,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | (4,000,000) | | (4,000,000) | | (2,000,000) |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,172,000,000 | | 1,172,000,000 | | 261,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss | (4,000,000) | | (4,000,000) | | (2,000,000) |
Operating Segments [Member] | Automotive | Non-U.S. government and agencies | | | | | |
Schedule of Available-for-sale Securities [Line Items] | | | | | |
Available-for-sale Securities, Amortized Cost Basis | 2,961,000,000 | | 2,961,000,000 | | 1,443,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax | 5,000,000 | | 5,000,000 | | 1,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax | (5,000,000) | | (5,000,000) | | (11,000,000) |
Available-for-sale Securities | 2,961,000,000 | | 2,961,000,000 | | 1,433,000,000 |
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value | 248,000,000 | | 248,000,000 | | 148,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value | 2,688,000,000 | | 2,688,000,000 | | 1,285,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value | 25,000,000 | | 25,000,000 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] | | | | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 1,555,000,000 | | 1,555,000,000 | | 1,137,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | (5,000,000) | | (5,000,000) | | (11,000,000) |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,555,000,000 | | 1,555,000,000 | | 1,137,000,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss | (5,000,000) | | (5,000,000) | | (11,000,000) |
Operating Segments [Member] | Automotive | Corporate debt | | | | | |
Schedule of Available-for-sale Securities [Line Items] | | | | | |
Available-for-sale Securities, Amortized Cost Basis | 1,398,000,000 | | 1,398,000,000 | | 1,079,000,000 |
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax | 0 | | 0 | | 0 |
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax | (2,000,000) | | (2,000,000) | | 0 |
Available-for-sale Securities | 1,396,000,000 | | 1,396,000,000 | | 1,079,000,000 |
Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value | 756,000,000 | | 756,000,000 | | 1,031,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value | 633,000,000 | | 633,000,000 | | 48,000,000 |
Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value | 7,000,000 | | 7,000,000 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] | | | | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 517,000,000 | | 517,000,000 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | (2,000,000) | | (2,000,000) | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 0 | | 0 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 517,000,000 | | 517,000,000 | | 0 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss | $ (2,000,000) | | $ (2,000,000) | | $ 0 |