Employee Benefit Plans Defined benefit pension plan obligations and funded status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	$ 18,103	$ 15,963
Interest cost	680	757	$ 702
Actuarial (gain) loss	(809)	2,460
Benefits paid	(797)	(1,077)
Projected benefit obligation at end of year	17,177	18,103	15,963
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	17,300	18,000
Actuarial (loss) gain on plan assets	(786)	377
Benefits paid	(797)	(1,077)
Fair value of plan assets at end of year	15,717	17,300	$ 18,000
Net liability for pension benefits	(1,460)	(803)
Accumulated benefit obligation at December 31	$ 17,177	$ 18,103