Retirement Benefit Plans (Schedule of Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 16	$ 14
Interest cost	1,131	1,199
Expected return on plan assets	(1,567)	(1,471)
Amortization of prior service cost	0	0
Amortization of net (gain)/loss	703	659
Net periodic benefit cost	283	401
Supplemental Employee Retirement Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	114	101
Interest cost	102	104
Amortization of prior service cost	327	287
Net periodic benefit cost	543	492
Hourly Employees’ Pension Plan | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	11	10
Interest cost	371	411
Expected return on plan assets	(549)	(520)
Amortization of prior service cost	0	0
Amortization of net (gain)/loss	285	280
Net periodic benefit cost	118	181
Employees’ Retirement Plan | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	4
Interest cost	760	788
Expected return on plan assets	(1,018)	(951)
Amortization of prior service cost	0	0
Amortization of net (gain)/loss	418	379
Net periodic benefit cost	$ 165	$ 220