Defined Benefit Pension Plans Schedule of Net Periodic Pension Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of Net Periodic Pension Benefit Costs [Line Items]
Service cost	$ 986	$ 1,089
Interest cost	633	620
Expected return on plan assets	(126)	(136)
Settlements and other	(3)	(1)
Amortization of actuarial net loss	327	497
Amortization of unrecognized prior service costs	15	15
Net periodic benefit cost	$ 1,832	$ 2,084