Schedule of Net Periodic Pension Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Net Periodic Pension Benefit Costs [Line Items]
Service cost	$ 1,003	$ 904	$ 2,930	$ 3,162
Interest cost	649	595	1,932	1,820
Expected return on plan assets	(139)	(122)	(398)	(387)
Settlements and other	506	375	499	374
Amortization of actuarial net loss	330	488	991	1,470
Amortization of unrecognized prior service costs	16	14	47	43
Net periodic benefit cost	$ 2,365	$ 2,254	$ 6,001	$ 6,482