5. Goodwill and Other intangible assets

At December 31, 2018 and 2017, Goodwill was $15.3 billion and $15.5 billion, respectively, and Other intangible assets were $6.1 billion and $6.5 billion, respectively.

a) Goodwill

The following table presents a roll-forward of Goodwill by segment:



(in millions of U.S. dollars)	North America Commercial P&C Insurance			North America Personal P&C Insurance			North America Agricultural Insurance		Overseas General Insurance			Global Reinsurance		Life Insurance			Chubb Consolidated
Balance at December 31, 2016	$	6,961		$	2,235		$	134	$	4,817		$	365	$	820		$	15,332
Foreign exchange revaluation and other	15			5			—		187			—		2			209
Balance at December 31, 2017	$	6,976		$	2,240		$	134	$	5,004		$	365	$	822		$	15,541
Foreign exchange revaluation and other	(30		)	(10		)	—		(234		)	6		(2		)	(270		)
Balance at December 31, 2018	$	6,946		$	2,230		$	134	$	4,770		$	371	$	820		$	15,271

b) Other intangible assets

The majority of the Other intangible assets balance at December 31, 2018 relates to the Chubb Corp acquisition and comprised of $3.2 billion that are subject to amortization, principally Agency distribution relationships and renewal rights, and $2.9 billion that are not subject to amortization, principally trademarks. This compares to $3.5 billion and $3.0 billion at December 31, 2017, respectively.

Amortization of purchased intangibles

Amortization expense related to purchased intangibles were $339 million, $260 million, and $19 million for the years ended December 31, 2018, 2017, and 2016, respectively. The increase in amortization expense of purchased intangibles in 2018 and 2017 compared to 2016, primarily reflects a lower amortization benefit from the fair value adjustment on acquired Unpaid losses and loss expenses related to the Chubb Corp acquisition.

The following table presents, as of December 31, 2018, the expected estimated pre-tax amortization expense (benefit) of purchased intangibles, at current foreign currency exchange rates, for the next five years:



	Associated with the Chubb Corp Acquisition
For the Year Ending December 31 (in millions of U.S. dollars)	Agency distribution relationships and renewal rights		Fair value adjustment on Unpaid losses and loss expense ⁽¹⁾			Total		Other intangible assets		Total Amortization of purchased intangibles
2019	$	280	$	(62	)	$	218	$	80	$	298
2020	239		(35		)	204		76		280
2021	216		(20		)	196		70		266
2022	196		(14		)	182		64		246
2023	177		(7		)	170		62		232
Total	$	1,108	$	(138	)	$	970	$	352	$	1,322

⁽¹⁾

In connection with the Chubb Corp acquisition, we recorded an increase to Unpaid losses and loss expenses acquired to adjust the carrying value of Chubb Corp's historical Unpaid losses and loss expenses to fair value as of the acquisition date. This fair value adjustment amortizes through Amortization of purchased intangibles on the Consolidated statements of operations through the year 2032. The balance of the fair value adjustment on Unpaid losses and loss expense was $207 million and $309 million at December 31, 2018 and 2017, respectively. Refer to Note 1(h) for additional information.

c) VOBA

The following table presents a roll-forward of VOBA:



(in millions of U.S. dollars)	2018			2017			2016
Balance, beginning of year	$	326		$	355		$	395
Amortization of VOBA ⁽¹⁾	(25		)	(35		)	(41		)
Foreign exchange revaluation	(6		)	6			1
Balance, end of year	$	295		$	326		$	355


⁽¹⁾	Recognized in Policy acquisition costs in the Consolidated statements of operations.

The following table presents, as of December 31, 2018, the expected estimated pre-tax amortization expense related to VOBA for the next five years:



For the Year Ending December 31	VOBA
(in millions of U.S. dollars)	VOBA
2019	$	26
2020	24
2021	22
2022	20
2023	18
Total	$	110