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Bank segment - Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Not designated as a hedging instrument
Derivative instrument
Asset derivatives	$ 486		$ 486		$ 91
Liability derivatives	92		92		43
Net gains (losses) recognized in the Statement of Income	36	$ (186)	346	$ (107)
Interest rate lock commitments
Derivative instrument
Notional amount	42,073		42,073		10,180
Fair value	470		470		91
Interest rate lock commitments \| Not designated as a hedging instrument
Derivative instrument
Asset derivatives	477		477		91
Liability derivatives	7		7		0
Interest rate lock commitments \| Not designated as a hedging instrument \| Mortgage banking income
Derivative instrument
Net gains (losses) recognized in the Statement of Income	(3)	(248)	379	(131)
Forward commitments
Derivative instrument
Notional amount	55,791		55,791		10,132
Fair value	(76)		(76)		(43)
Forward commitments \| Not designated as a hedging instrument
Derivative instrument
Asset derivatives	9		9		0
Liability derivatives	85		85		$ 43
Forward commitments \| Not designated as a hedging instrument \| Mortgage banking income
Derivative instrument
Net gains (losses) recognized in the Statement of Income	$ 39	$ 62	$ (33)	$ 24