Bank segment - Troubled debt restructuring that subsequently defaulted (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016 USD ($) contract	Jun. 30, 2016 USD ($) contract
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1	2
Recorded investment | $	$ 26	$ 514
Residential 1-4 family
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	1
Recorded investment | $	$ 0	$ 488
Commercial loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1	1
Recorded investment | $	$ 26	$ 26