Goodwill and other intangibles (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of goodwill

The summary of changes in goodwill is as follows:

	Title		Ancillary Services and Corporate		Total
	($000 omitted)
Balances at January 1, 2016	211,255		6,467		217,722
Acquisitions	300		—		300
Disposals	(190	)	(738	)	(928	)
Balances at December 31, 2016	211,365		5,729		217,094
Acquisitions	14,419		—		14,419
Disposals	(85	)	—		(85	)
Balances at December 31, 2017	225,699		5,729		231,428