Employee Benefit Plans Defined benefit pension plan obligations and funded status (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	$ 20,832
Interest cost	599
Settlement gain	(326)
Actuarial gain	(2,667)
Benefits paid	(712)
Settlement payments	(17,726)
Projected benefit obligation at end of year	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	18,499
Actuarial loss on plan assets	(717)
Administration expenses	(194)
Employer contributions	850
Benefits paid	(712)
Settlement payments	(17,726)
Fair value of plan assets at end of year	0
Net liability for pension benefits	$ 0