Pension - Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Components of net periodic benefit cost:
Interest cost	$ 15	$ 18	$ 44	$ 53
Service cost	6	6	19	19
Expected return on plan assets	(24)	(23)	(70)	(70)
Amortization of prior service costs	2	2	7	7
Amortization of actuarial loss	36	29	92	87
Net periodic benefit cost	$ 35	$ 32	$ 92	$ 96