Postretirement benefits (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of Net Funded Status [Table Text Block]

Obligations and funded status

The funded status of the pension and other postretirement benefit plans as well as the amounts recognized in Accumulated other comprehensive income at December 31, 2017 and 2016 was as follows:



	Pension Benefits												Other Postretirement Benefits
	2017						2016						2017			2016
	U.S. Plans			Non-U.S. Plans			U.S. Plans			Non-U.S. Plans
(in millions of U.S. dollars)	U.S. Plans			Non-U.S. Plans			U.S. Plans			Non-U.S. Plans
Benefit obligation, beginning of year	$	3,035		$	1,025		$	10		$	559		$	165		$	16
Acquisition of Chubb Corp	—			—			3,153			372			—			506
Service cost	63			17			75			18			2			10
Interest cost	105			27			103			30			4			17
Actuarial loss (gain)	232			(4		)	131			204			(2		)	36
Benefits paid	(132		)	(28		)	(79		)	(22		)	(14		)	(11		)
Amendments	—			—			—			(9		)	(23		)	(410		)
Curtailments	—			(32		)	(259		)	(7		)	2			—
Settlements	(18		)	(8		)	(99		)	(7		)	—			—
Foreign currency revaluation and other	—			80			—			(113		)	3			1
Benefit obligation, end of year	$	3,285		$	1,077		$	3,035		$	1,025		$	137		$	165
Plan assets at fair value, beginning of year	$	2,765		$	962		$	9		$	564		$	159		$	—
Acquisition of Chubb Corp	—			—			2,473			315			—			138
Actual return on plan assets	441			100			359			168			6			29
Employer contributions	53			63			98			67			6			3
Benefits paid	(132		)	(28		)	(79		)	(22		)	(14		)	(11		)
Settlements	(18		)	(8		)	(95		)	(7		)	—			—
Foreign currency revaluation and other	—			83			—			(123		)	—			—
Plan assets at fair value, end of year	$	3,109		$	1,172		$	2,765		$	962		$	157		$	159
Funded status at end of year	$	(176	)	$	95		$	(270	)	$	(63	)	$	20		$	(6	)
Amounts recognized in Accumulated other comprehensive income, not yet recognized in net periodic cost (benefit):
Net actuarial loss (gain)	$	(227	)	$	82		$	(207	)	$	156		$	12		$	17
Prior service cost (benefit)	—			6			—			(2		)	(288		)	(395		)
Total	$	(227	)	$	88		$	(207	)	$	154		$	(276	)	$	(378	)

Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]

Schedule of Assumptions Used [Table Text Block]

The weighted-average assumptions used to determine the projected benefit obligation were as follows:



	Pension Benefits
	U.S. Plans		Non-U.S. Plans		Other Postretirement Benefits
	U.S. Plans		Non-U.S. Plans		Other Postretirement Benefits
December 31, 2017
Discount rate	3.59	%	2.76	%	2.77	%
Rate of compensation increase	4.00	%	3.46	%	N/A
December 31, 2016
Discount rate	4.14	%	2.83	%	2.97	%
Rate of compensation increase	4.00	%	3.57	%	N/A

The components of net pension and other postretirement benefit costs reflected in Net income and other changes in plan assets and benefit obligations recognized in other comprehensive income were as follows:



	Pension Benefits																	Other Postretirement Benefits
	U.S. Plans								Non-U.S. Plans
Year Ended December 31	2017			2016			2015		2017			2016			2015			2017			2016			2015
(in millions of U.S. dollars)	2017			2016			2015		2017			2016			2015			2017			2016			2015
Costs reflected in Net income:
Service cost	$	63		$	75		$	—	$	17		$	18		$	6		$	2		$	10		$	1
Interest cost	105			103			—		27			30			21			4			17			—
Expected return on plan assets	(189		)	(165		)	—		(42		)	(39		)	(29		)	(5		)	(8		)	—
Amortization of net actuarial loss (gain)	—			—			—		3			2			2			—			(1		)	(1		)
Amortization of prior service cost	—			—			—		—			(1		)	—			(89		)	(15		)	—
Curtailments	—			(117		)	—		(27		)	—			—			(37		)	—			—
Settlements	—			(2		)	—		—			1			1			—			—			—
Net periodic (benefit) cost	$	(21	)	$	(106	)	$	—	$	(22	)	$	11		$	1		$	(125	)	$	3		$	—
Changes in plan assets and benefit obligations recognized in other comprehensive income
Net actuarial loss (gain)	$	(21	)	$	(326	)	$	—	$	(57	)	$	49		$	(16	)	$	(3	)	$	17		$	—
Prior service cost (benefit)	—			—			—		—			(8		)	1			(23		)	(395		)	—
Amortization of net actuarial loss	—			—			—		(3		)	—			—			—			—			—
Amortization of prior service cost	—			—			—		—			—			—			89			—			—
Curtailments	—			117			—		(6		)	—			—			39			—			—
Settlements	1			2			—		—			(1		)	—			—			—			—
Total (increase) decrease in other comprehensive income	$	(20	)	$	(207	)	$	—	$	(66	)	$	40		$	(15	)	$	102		$	(378	)	$	—

The estimated net actuarial loss that will be amortized from AOCI into net periodic benefit costs in Net income for Non-U.S. pension plans during 2018 is $1 million. The estimated net prior service credit that will be amortized from AOCI into net periodic benefit cost in Net income during 2018 for U.S. other postretirement benefit plans is $80 million.

The weighted-average assumptions used to determine the net periodic pension and other postretirement benefit costs were as follows:



	Pension Benefits
	U.S. Plans		Non-U.S. Plans		Other Postretirement Benefits
Year Ended December 31	U.S. Plans		Non-U.S. Plans		Other Postretirement Benefits
2017
Discount rate in effect for determining service cost	4.20	%	3.55	%	2.84	%
Discount rate in effect for determining interest cost	3.53	%	2.61	%	2.44	%
Rate of compensation increase	4.00	%	3.57	%	N/A
Expected long-term rate of return on plan assets	7.00	%	4.23	%	3.00	%
2016
Discount rate in effect for determining service cost	4.38	%	3.85	%	4.32	%
Discount rate in effect for determining interest cost	3.59	%	3.44	%	4.02	%
Rate of compensation increase	4.00	%	3.33	%	N/A
Expected long-term rate of return on plan assets	7.00	%	4.79	%	6.34	%
2015
Discount rate	NM		3.51	%	NM
Rate of compensation increase	NM		3.09	%	NM
Expected long-term rate of return on plan assets	NM		4.81	%	NM
NM – not meaningful

Schedule of Net Benefit Costs [Table Text Block]



	Pension Benefits																	Other Postretirement Benefits
	U.S. Plans								Non-U.S. Plans
Year Ended December 31	2017			2016			2015		2017			2016			2015			2017			2016			2015
(in millions of U.S. dollars)	2017			2016			2015		2017			2016			2015			2017			2016			2015
Costs reflected in Net income:
Service cost	$	63		$	75		$	—	$	17		$	18		$	6		$	2		$	10		$	1
Interest cost	105			103			—		27			30			21			4			17			—
Expected return on plan assets	(189		)	(165		)	—		(42		)	(39		)	(29		)	(5		)	(8		)	—
Amortization of net actuarial loss (gain)	—			—			—		3			2			2			—			(1		)	(1		)
Amortization of prior service cost	—			—			—		—			(1		)	—			(89		)	(15		)	—
Curtailments	—			(117		)	—		(27		)	—			—			(37		)	—			—
Settlements	—			(2		)	—		—			1			1			—			—			—
Net periodic (benefit) cost	$	(21	)	$	(106	)	$	—	$	(22	)	$	11		$	1		$	(125	)	$	3		$	—
Changes in plan assets and benefit obligations recognized in other comprehensive income
Net actuarial loss (gain)	$	(21	)	$	(326	)	$	—	$	(57	)	$	49		$	(16	)	$	(3	)	$	17		$	—
Prior service cost (benefit)	—			—			—		—			(8		)	1			(23		)	(395		)	—
Amortization of net actuarial loss	—			—			—		(3		)	—			—			—			—			—
Amortization of prior service cost	—			—			—		—			—			—			89			—			—
Curtailments	—			117			—		(6		)	—			—			39			—			—
Settlements	1			2			—		—			(1		)	—			—			—			—
Total (increase) decrease in other comprehensive income	$	(20	)	$	(207	)	$	—	$	(66	)	$	40		$	(15	)	$	102		$	(378	)	$	—

Schedule of Health Care Cost Trend Rates [Table Text Block]

The weighted-average healthcare cost trend rate assumptions used to measure the expected cost of healthcare benefits were as follows:



	U.S. Plans						Non-U.S. Plans
	2017		2016		2015		2017		2016
Healthcare cost trend rate	7.01	%	7.28	%	6.50	%	6.61	%	6.61	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50	%	4.50	%	4.50	%	4.50	%	4.50	%
Year that the rate reaches the ultimate trend rate	2038		2038		2026		2029		2029

Schedule of Allocation of Plan Assets [Table Text Block]

The following table presents the fair values of the pension plan assets, by valuation hierarchy. For additional information on how we classify these assets within the valuation hierarchy, refer to Note 4 to the Consolidated financial statements.



December 31, 2017	Pension Benefits
(in millions of U.S. dollars)	Level 1		Level 2		Level 3		Total
U.S. Plans:
Short-term investments	$	9	$	52	$	—	$	61
U.S. Treasury and agency	446		79		—		525
Foreign and corporate bonds	—		692		—		692
Equity securities	1,154		—		—		1,154
Total U.S. Plan assets ⁽¹⁾	$	1,609	$	823	$	—	$	2,432
Non-U.S. Plans:
Short-term investments	$	5	$	—	$	—	$	5
Foreign and corporate bonds	—		456		—		456
Equity securities	122		492		—		614
Total Non-U.S. Plan assets⁽¹⁾	$	127	$	948	$	—	$	1,075


⁽¹⁾	Excluded from the table above are $677 million and $95 million of other investments measured using NAV as a practical expedient related to the U.S. Plans and non-U.S. Plans respectively.



December 31, 2016	Pension Benefits
(in millions of U.S. dollars)	Level 1		Level 2		Level 3		Total
U.S. Plans:
Short-term investments	$	—	$	43	$	—	$	43
U.S. Treasury and agency	206		112		—		318
Foreign and corporate bonds	—		482		5		487
Equity securities	728		—		—		728
Derivative instruments	3		—		—		3
Total U.S. Plan assets ⁽¹⁾	$	937	$	637	$	5	$	1,579
Non-U.S. Plans:
Short-term investments	$	2	$	—	$	—	$	2
Foreign and corporate bonds	—		435		—		435
Equity securities	100		412		—		512
Total Non-U.S. Plan assets ⁽¹⁾	$	102	$	847	$	—	$	949


⁽¹⁾	Excluded from the table above are $1.2 billion and $13 million of other investments measured using NAV as a practical expedient related to the U.S. Plans and Non-U.S. Plans, re

Schedule of expected future benefit payments

Expected future payments are as follows:



	Pension
For the years ending December 31	U.S. Plans		Non-U.S. Plans		Other Postretirement Benefits
(in millions of U.S. dollars)	U.S. Plans		Non-U.S. Plans		Other Postretirement Benefits
2018	$	129	$	23	$	17
2019	141		25		19
2020	148		29		20
2021	155		28		23
2022	163		27		25
2023-2027	881		159		44