Defined Benefit Pension Plans (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		120 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 30, 2023
Qualified Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 614	$ 538	$ 1,229	$ 1,076
Interest cost	732	722	1,464	1,445
Expected return on plan assets	(1,128)	(1,015)	(2,257)	(2,031)
Amortization of prior service cost	(5)	(5)	(11)	(11)
Recognized net actuarial loss	312	115	624	230
Net periodic benefit cost	525	355	1,049	709
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	19	11	39	23
Interest cost	123	119	245	239
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	0	0	0	0
Recognized net actuarial loss	61	19	122	35
Net periodic benefit cost	$ 203	$ 149	$ 406	$ 297
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Transition Period Pension Plan Amendment					10 years