Defined Benefit Pension Plans (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		120 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 30, 2023
Qualified Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 615	$ 538	$ 1,844	$ 1,614
Interest cost	731	723	2,195	2,168
Expected return on plan assets	(1,129)	(1,016)	(3,386)	(3,047)
Amortization of prior service (credit) cost	(6)	(6)	(17)	(17)
Recognized net actuarial loss	313	115	937	345
Net periodic benefit cost	524	354	1,573	1,063
Non-Qualified Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	20	11	59	34
Interest cost	122	119	367	358
Expected return on plan assets	0	0	0	0
Amortization of prior service (credit) cost	0	0	0	0
Recognized net actuarial loss	61	18	183	53
Net periodic benefit cost	$ 203	$ 148	$ 609	$ 445
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Transition Period Pension Plan Amendment					10 years