Pension Benefits (Tables)

12 Months Ended

Dec. 31, 2017

Defined Benefit Plan Disclosure [Line Items]

Schedule of Accumulated and Projected Benefit Obligations

The projected benefit obligation (“PBO”), accumulated benefit obligation (“ABO”), and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets and with plan assets in excess of accumulated benefit obligations are as follows:

	U.S. Plans				Non-U.S. Plans
	2017		2016		2017		2016
	(in millions) Plans with ABO in Excess of Plan Assets
PBO	$	29	$	40	$	743	$	2,030
ABO	29		40		701		1,805
Fair value of plan assets at end of year	—		—		282		1,100
	Plans with Plan Assets in Excess of ABO
PBO	$	—	$	—	$	92	$	107
ABO	—		—		64		74
Fair value of plan assets at end of year	—		—		95		112
	Total
PBO	$	29	$	40	$	835	$	2,137
ABO	29		40		765		1,879
Fair value of plan assets at end of year	—		—		377		1,212

Schedule of Assumptions Used

Assumptions used to determine benefit obligations at December 31:

	Pension Benefits
	U.S. Plans				Non-U.S. Plans
	2017		2016		2017		2016
Weighted-average discount rate	2.70	%	2.70	%	3.39	%	2.83	%
Weighted-average rate of increase in compensation levels	N/A		N/A		3.65	%	3.86	%

Assumptions used to determine net expense for years ended December 31:

	Pension Benefits
	U.S. Plans						Non-U.S. Plans
	2017		2016		2015		2017		2016		2015
Weighted-average discount rate	2.70	%	2.70	%	2.50	%	2.83	%	3.81	%	3.67	%
Weighted-average rate of increase in compensation levels	N/A		N/A		N/A		3.86	%	3.67	%	3.65	%
Weighted-average expected long-term rate of return on plan assets	N/A		N/A		N/A		5.84	%	5.84	%	6.34	%

Schedule of Change in Assumptions Used

’s pension expense for 2018 is determined at the 2017 year end measurement date. For purposes of analysis, the following table highlights the sensitivity of the Company’ pension obligations and expense attributable to continuing operations to changes in key assumptions:

Change in Assumption	Impact on Pension Expense	Impact on PBO
25 basis point (“bp”) decrease in discount rate	+ $2 million	+ $29 million
25 bp increase in discount rate	- $2 million	- $27 million
25 bp decrease in long-term expected return on assets	+ $1 million	—
25 bp increase in long-term expected return on assets	- $1 million	—

Schedule of Expected Benefit Payments

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid:

	Projected Pension Benefit Payments
	U.S. Plans		Non-U.S. Plans
	(in millions)
2018	$	10	$	52
2019	8		33
2020	4		35
2021	3		38
2022	1		39
2023 – 2027	3		242

Schedule of Allocation of Plan Assets

The fair values of Aptiv’s pension plan assets weighted-average asset allocations at December 31, 2017 and 2016, by asset category, are as follows:

	Fair Value Measurements at December 31, 2017
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in millions)
Cash	$	17	$	17	$	—	$	—
Time deposits	4		—		4		—
Equity mutual funds	114		—		114		—
Bond mutual funds	94		—		94		—
Real estate trust funds	13		—		—		13
Hedge funds	27		—		—		27
Insurance contracts	6		—		—		6
Debt securities	51		51		—		—
Equity securities	51		51		—		—
Total	$	377	$	119	$	212	$	46

	Fair Value Measurements at December 31, 2016
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in millions)
Cash	$	61	$	61	$	—	$	—
Time deposits	10		—		10		—
Equity mutual funds	423		—		423		—
Bond mutual funds	469		—		469		—
Real estate trust funds	29		—		—		29
Hedge funds	107		—		—		107
Insurance contracts	5		—		—		5
Debt securities	51		51		—		—
Equity securities	57		57		—		—
Total	$	1,212	$	169	$	902	$	141

Schedule of Level Three Defined Benefit Plan Assets Roll Forward

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Real Estate Trust Fund			Hedge Funds			Insurance Contracts
	(in millions)
Beginning balance at January 1, 2016	$	39		$	102		$	1
Actual return on plan assets:
Relating to assets still held at the reporting date	4			22			—
Purchases, sales and settlements	(10		)	—			4
Foreign currency translation and other	(4		)	(17		)	—
Ending balance at December 31, 2016	$	29		$	107		$	5
Actual return on plan assets:
Relating to assets still held at the reporting date	$	1		$	2		$	1
Purchases, sales and settlements	6			—			—
Spin-off of Delphi Technologies	(23		)	(84		)	—
Foreign currency translation and other	—			2			—
Ending balance at December 31, 2017	$	13		$	27		$	6

U.S. Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Funded Status

The amounts shown below reflect the change in the U.S. defined benefit pension obligations during 2017 and 2016.

	Year Ended December 31,
	2017			2016
	(in millions)
Benefit obligation at beginning of year	$	40		$	50
Interest cost	1			1
Benefits paid	(12		)	(11		)
Benefit obligation at end of year	29			40
Change in plan assets:
Fair value of plan assets at beginning of year	—			—
Aptiv contributions	12			11
Benefits paid	(12		)	(11		)
Fair value of plan assets at end of year	—			—
Underfunded status	(29		)	(40		)
Amounts recognized in the consolidated balance sheets consist of:
Current liabilities	(10		)	(11		)
Non-current liabilities	(19		)	(29		)
Total	(29		)	(40		)
Amounts recognized in accumulated other comprehensive income consist of (pre-tax):
Actuarial loss	9			10
Total	$	9		$	10

Schedule of Net Benefit Costs

Benefit costs presented below were determined based on actuarial methods and included the following, which include the results of discontinued operations:

	U.S. Plans
	Year Ended December 31,
	2017		2016		2015
	(in millions)
Interest cost	$	1	$	1	$	1
Amortization of actuarial losses	1		1		1
Net periodic benefit cost	$	2	$	2	$	2

Non-U.S. Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Funded Status

The amounts shown below reflect the change in the non-U.S. defined benefit pension obligations during 2017 and 2016.

	Year Ended December 31,
	2017			2016
	(in millions)
Benefit obligation at beginning of year	$	2,137		$	2,032
Service cost	48			46
Interest cost	54			63
Actuarial (gain) loss	(1		)	363
Benefits paid	(71		)	(84		)
Impact of curtailments	3			2
Spin-off of Delphi Technologies	(1,518		)	—
Exchange rate movements and other	183			(285		)
Benefit obligation at end of year	835			2,137
Change in plan assets:
Fair value of plan assets at beginning of year	1,212			1,209
Actual return on plan assets	75			204
Aptiv contributions	67			83
Benefits paid	(71		)	(84		)
Spin-off of Delphi Technologies	(997		)	—
Exchange rate movements and other	91			(200		)
Fair value of plan assets at end of year	377			1,212
Underfunded status	(458		)	(925		)
Amounts recognized in the consolidated balance sheets consist of:
Non-current assets	4			8
Current liabilities	(31		)	(10		)
Non-current liabilities	(431		)	(923		)
Total	(458		)	(925		)
Amounts recognized in accumulated other comprehensive income consist of (pre-tax):
Actuarial loss	144			505
Prior service cost	1			1
Total	$	145		$	506

Schedule of Net Benefit Costs

	Non-U.S. Plans
	Year Ended December 31,
	2017			2016			2015
	(in millions)
Service cost	$	48		$	46		$	57
Interest cost	54			63			77
Expected return on plan assets	(63		)	(65		)	(77		)
Settlement loss (1)	1			—			11
Curtailment loss (gain)	16			3			(3		)
Amortization of actuarial losses	35			14			18
Other	—			2			—
Net periodic benefit cost	$	91		$	63		$	83