Net Periodic Benefit Cost-Defined Benefit Plans (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Net periodic benefit cost of the domestic non-contributory defined benefit plan
Service cost	$ 17,000	$ 16,000	$ 51,000	$ 48,000
Interest cost	193,000	189,000	579,000	567,000
Expected return on plan assets	(251,000)	(246,000)	(753,000)	(737,000)
Amortization of net loss	39,000	39,000	117,000	119,000
Net periodic benefit cost	(2,000)	$ (2,000)	(6,000)	$ (3,000)
Expected contribution to Pension Plan in 2015 (minimum)					$ 500,000
Employer contributions made to the defined benefit plan			500,000
Anticipated additional contributions anticipated during the remainder of 2015 (at least)	$ 250,000		$ 250,000