Deferred tax reconciliation (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Change in net deferred income tax liability from the preceding table	$ 4,597
Deferred taxes associated with other comprehensive income	(825)
Other	(5,821)
Deferred income taxes	$ (2,049)	$ (25,356)	$ 54,963