Employee Benefit Plans (Schedule of Net Period Benefit Cost and Other Amounts Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Executive Retirement Plan [Member]
Net period benefit cost
Service cost	$ 308	$ 307	$ 270
Interest cost	432	424	456
Recognized net actuarial loss	220	218	140
Amortization of prior service cost (credit)	7	19	19
Net period benefit cost	967	968	885
Changes in funded status recognized in other comprehensive loss, before taxes
Net actuarial (gain) loss	219	(32)	777
Amortization of net unrecognized actuarial loss	(220)	(218)	(140)
Amortization of prior service (cost) credit	(7)	(19)	(19)
Total recognized in OCI, before taxes	(8)	(269)	618
Total recognized in net period benefit cost and OCI, before taxes	959	699	1,503
Other Postretirement Benefit Plan [Member]
Net period benefit cost
Service cost	59	62	45
Interest cost	151	117	132
Recognized net actuarial loss	30	24	10
Amortization of prior service cost (credit)	(22)	(22)	(22)
Net period benefit cost	218	181	165
Changes in funded status recognized in other comprehensive loss, before taxes
Net actuarial (gain) loss	143	92	(134)
Amortization of net unrecognized actuarial loss	(30)	(24)	(10)
Amortization of prior service (cost) credit	22	22	22
Total recognized in OCI, before taxes	135	90	(122)
Total recognized in net period benefit cost and OCI, before taxes	$ 353	$ 271	$ 43