Employee Benefit Plans (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Plans, Defined Benefit
Components of net periodic benefit costs:
Interest cost	$ 110,000	$ 111,000	$ 329,000	$ 335,000
Expected return on plan assets	(123,000)	(122,000)	(369,000)	(373,000)
Amortization of net loss	23,000	28,000	71,000	92,000
Settlement of benefit obligation	0	(82,000)	0	(454,000)
Net periodic benefit/cost	10,000	99,000	31,000	508,000
Other Postretirement Benefit Plans, Defined Benefit
Components of net periodic benefit costs:
Interest cost	1,000	2,000	3,000	4,000
Amortization of net loss	(2,000)	(2,000)	(5,000)	(4,000)
Net periodic benefit/cost	$ (1,000)	$ 0	$ (2,000)	$ 0
Other Postretirement Benefit Plans, Defined Benefit | Employees Hired before January 1, 2003
Components of net periodic benefit costs:
Benefit based on highest average salary for number of consecutive years			5 years
Number of years for consecutive years calculation			10 years
Other Postretirement Benefit Plans, Defined Benefit | Employees Hired on or after January 1, 2003
Components of net periodic benefit costs:
Percent of annual salary to calculate benefit			2.00%