Employee Benefit Plans (Components of Postretirement Benefit Expense) (Details) - Postretirement Medical and Life Benefit Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 42	$ 41	$ 40
Interest Cost	26	28	23
Amortization of Unrecognized Net (Gain) Loss	5	0	4
Net Postretirement Benefit Expense	73	69	67
Net (Gain) Loss During Period Recognized in Other Comprehensive Income (Loss)	17	46	(37)
Total Recognized in Net Postretirement Benefit Expense and Other Comprehensive Income	$ 90	$ 115	$ 30