Other expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Income and Expenses [Abstract]
Deposit liabilities investment expense	$ 860	$ 1,352	$ 1,331	$ 1,983
Reinsurance contracts investment expense	2,167	1,533	4,637	3,303
Change in fair value of embedded derivatives in deposit and reinsurance contracts	146	(570)	(89)	(270)
Other expenses	$ 3,173	$ 2,315	$ 5,879	$ 5,016