Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Assets:
Total	$ 1,578	$ 2,704
Other liabilities:
Total	2,271	1,298
Interest rate swaps | Prepaid expenses and other
Assets:
Derivative asset	217
Interest rate swaps | Other assets
Assets:
Derivative asset	283	787
Interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	4
Interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities	612	303
Cross currency swaps | Prepaid expenses and other
Assets:
Derivative asset	10
Cross currency swaps | Other assets
Assets:
Derivative asset	620	1,446
Cross currency swaps | Other current liabilities
Other liabilities:
Derivative liabilities	197
Cross currency swaps | Other liabilities
Other liabilities:
Derivative liabilities	1,165	196
Fixed income securities | Other assets
Assets:
Debt securities, available-for-sale	448	459
Foreign exchange forwards | Prepaid expenses and other
Assets:
Derivative asset		12
Foreign exchange forwards | Other current liabilities
Other liabilities:
Derivative liabilities	12	2
Forward starting interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	281	409
Forward starting interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities		388
Level 1
Assets:
Total	0	0
Other liabilities:
Total	0	0
Level 1 | Interest rate swaps | Prepaid expenses and other
Assets:
Derivative asset	0
Level 1 | Interest rate swaps | Other assets
Assets:
Derivative asset	0	0
Level 1 | Interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	0
Level 1 | Interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities	0	0
Level 1 | Cross currency swaps | Prepaid expenses and other
Assets:
Derivative asset	0
Level 1 | Cross currency swaps | Other assets
Assets:
Derivative asset	0	0
Level 1 | Cross currency swaps | Other current liabilities
Other liabilities:
Derivative liabilities	0
Level 1 | Cross currency swaps | Other liabilities
Other liabilities:
Derivative liabilities	0	0
Level 1 | Fixed income securities | Other assets
Assets:
Debt securities, available-for-sale	0	0
Level 1 | Foreign exchange forwards | Prepaid expenses and other
Assets:
Derivative asset		0
Level 1 | Foreign exchange forwards | Other current liabilities
Other liabilities:
Derivative liabilities	0	0
Level 1 | Forward starting interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	0	0
Level 1 | Forward starting interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities		0
Level 2
Assets:
Total	1,578	2,704
Other liabilities:
Total	2,271	1,298
Level 2 | Interest rate swaps | Prepaid expenses and other
Assets:
Derivative asset	217
Level 2 | Interest rate swaps | Other assets
Assets:
Derivative asset	283	787
Level 2 | Interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	4
Level 2 | Interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities	612	303
Level 2 | Cross currency swaps | Prepaid expenses and other
Assets:
Derivative asset	10
Level 2 | Cross currency swaps | Other assets
Assets:
Derivative asset	620	1,446
Level 2 | Cross currency swaps | Other current liabilities
Other liabilities:
Derivative liabilities	197
Level 2 | Cross currency swaps | Other liabilities
Other liabilities:
Derivative liabilities	1,165	196
Level 2 | Fixed income securities | Other assets
Assets:
Debt securities, available-for-sale	448	459
Level 2 | Foreign exchange forwards | Prepaid expenses and other
Assets:
Derivative asset		12
Level 2 | Foreign exchange forwards | Other current liabilities
Other liabilities:
Derivative liabilities	12	2
Level 2 | Forward starting interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	281	409
Level 2 | Forward starting interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities		388
Level 3
Assets:
Total	0	0
Other liabilities:
Total	0	0
Level 3 | Interest rate swaps | Prepaid expenses and other
Assets:
Derivative asset	0
Level 3 | Interest rate swaps | Other assets
Assets:
Derivative asset	0	0
Level 3 | Interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	0
Level 3 | Interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities	0	0
Level 3 | Cross currency swaps | Prepaid expenses and other
Assets:
Derivative asset	0
Level 3 | Cross currency swaps | Other assets
Assets:
Derivative asset	0	0
Level 3 | Cross currency swaps | Other current liabilities
Other liabilities:
Derivative liabilities	0
Level 3 | Cross currency swaps | Other liabilities
Other liabilities:
Derivative liabilities	0	0
Level 3 | Fixed income securities | Other assets
Assets:
Debt securities, available-for-sale	0	0
Level 3 | Foreign exchange forwards | Prepaid expenses and other
Assets:
Derivative asset		0
Level 3 | Foreign exchange forwards | Other current liabilities
Other liabilities:
Derivative liabilities	0	0
Level 3 | Forward starting interest rate swaps | Other current liabilities
Other liabilities:
Derivative liabilities	$ 0	0
Level 3 | Forward starting interest rate swaps | Other liabilities
Other liabilities:
Derivative liabilities		$ 0