Fair Value Measurements - Input Hierarchy of Items Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions | Jun. 30, 2015 | Dec. 31, 2014 |
Automotive [Member] | | |
Assets [Abstract] | | |
Derivative financial instruments assets | $ 521 | $ 517 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 992 | 713 |
Financial Services [Member] | | |
Assets [Abstract] | | |
Derivative financial instruments assets | 823 | 859 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 378 | 167 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 267 | 206 |
Marketable securities | 14,599 | 17,135 |
Derivative financial instruments assets | 521 | 517 |
Total assets at fair value | 15,387 | 17,858 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 992 | 713 |
Total liabilities at fair value | 992 | 713 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Cash equivalents - financial instruments [Member] | | |
Input Hierarchy of Items Measured at Fair Value on Recurring Basis [Abstract] | | |
Par Value Assets Excluded From Fair Value By Input | 4,600 | 3,300 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Cash [Member] | | |
Input Hierarchy of Items Measured at Fair Value on Recurring Basis [Abstract] | | |
Par Value Assets Excluded From Fair Value By Input | 1,200 | 1,100 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 8 | 64 |
Marketable securities | 4,552 | 6,758 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 249 | 122 |
Marketable securities | 6,068 | 7,004 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 10 | 20 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 3,617 | 2,738 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Equities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 15 | 322 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 347 | 313 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 861 | 1,291 |
Derivative financial instruments assets | 0 | 0 |
Total assets at fair value | 861 | 1,291 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 0 | 0 |
Total liabilities at fair value | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 846 | 969 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | Equities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 15 | 322 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 1 [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 267 | 206 |
Marketable securities | 13,738 | 15,844 |
Derivative financial instruments assets | 521 | 517 |
Total assets at fair value | 14,526 | 16,567 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 991 | 710 |
Total liabilities at fair value | 991 | 710 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 8 | 64 |
Marketable securities | 3,706 | 5,789 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 249 | 122 |
Marketable securities | 6,068 | 7,004 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 10 | 20 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 3,617 | 2,738 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | Equities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 2 [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 347 | 313 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Derivative financial instruments assets | 0 | 0 |
Total assets at fair value | 0 | 0 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 1 | 3 |
Total liabilities at fair value | 1 | 3 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | Equities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Automotive [Member] | Level 3 [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 469 | 351 |
Marketable securities | 3,806 | 3,258 |
Derivative financial instruments assets | 823 | 859 |
Total assets at fair value | 5,098 | 4,468 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 378 | 167 |
Total liabilities at fair value | 378 | 167 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Cash equivalents - financial instruments [Member] | | |
Input Hierarchy of Items Measured at Fair Value on Recurring Basis [Abstract] | | |
Par Value Assets Excluded From Fair Value By Input | 3,900 | 3,800 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Cash [Member] | | |
Input Hierarchy of Items Measured at Fair Value on Recurring Basis [Abstract] | | |
Par Value Assets Excluded From Fair Value By Input | 2,400 | 2,000 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Marketable securities | 1,369 | 1,268 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 419 | 341 |
Marketable securities | 630 | 405 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 50 | 10 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 1,780 | 1,555 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 27 | 30 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 1 [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 669 | 17 |
Derivative financial instruments assets | 0 | 0 |
Total assets at fair value | 669 | 17 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 0 | 0 |
Total liabilities at fair value | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 1 [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Marketable securities | 669 | 17 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 1 [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 1 [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 1 [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 1 [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 2 [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 469 | 351 |
Marketable securities | 3,137 | 3,241 |
Derivative financial instruments assets | 823 | 859 |
Total assets at fair value | 4,429 | 4,451 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 378 | 167 |
Total liabilities at fair value | 378 | 167 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 2 [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Marketable securities | 700 | 1,251 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 2 [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 419 | 341 |
Marketable securities | 630 | 405 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 2 [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 50 | 10 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 2 [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 1,780 | 1,555 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 2 [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | 27 | 30 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 3 [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Derivative financial instruments assets | 0 | 0 |
Total assets at fair value | 0 | 0 |
Derivative financial instruments liabilities | | |
Derivative financial instruments liabilities | 0 | 0 |
Total liabilities at fair value | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 3 [Member] | US Treasury and Government [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 3 [Member] | Foreign Government and Agencies [Member] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 3 [Member] | Corporate Debt [Domain] | | |
Assets [Abstract] | | |
Cash equivalents - financial instruments | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 3 [Member] | Corporate Debt [Member] | | |
Assets [Abstract] | | |
Marketable securities | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Financial Services [Member] | Level 3 [Member] | Other marketable securities [Member] | | |
Assets [Abstract] | | |
Marketable securities | $ 0 | $ 0 |