Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	$ (80,923,000)		$ (116,840,000)
Other comprehensive income before reclassifications	0		(45,000)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	59,000	[1]	104,000	[1]
Amounts reclassified from accumulated other comprehensive loss, Actuarial loss	444,000	[2]	851,000	[2]
Amounts reclassified from accumulated other comprehensive loss, tax	(149,000)		(4,950,000)
Ending balance	(80,420,000)		(115,930,000)
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Loss [Roll Forward]
Net current-period other comprehensive income	503,000		910,000
Gains and Losses on Derivatives
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance			(1,009,000)
Other comprehensive income before reclassifications			(45,000)
Ending balance			(950,000)
Gains and Losses on Derivatives | Interest rate swaps
Accumulated Other Comprehensive Loss [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			104,000	[1]
Gains and Losses on Derivatives | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Loss [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss, Actuarial loss			0	[2]
Net current-period other comprehensive income			59,000
Gains and Losses on Derivatives | Reclassification out of Accumulated Other Comprehensive Income | Interest rate swaps
Accumulated Other Comprehensive Loss [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss, tax			62,000
Defined Benefit Pension Items
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(80,377,000)		(116,188,000)
Other comprehensive income before reclassifications	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	[1]	0	[1]
Ending balance	(79,933,000)		(115,337,000)
Defined Benefit Pension Items | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Loss [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss, Actuarial loss	444,000	[2]	851,000	[2]
Amounts reclassified from accumulated other comprehensive loss, tax	280,000		298,000
Net current-period other comprehensive income	444,000		851,000
Other
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	172,000		357,000
Other comprehensive income before reclassifications	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	[1]	0	[1]
Ending balance	172,000		357,000
Other | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Loss [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss, Actuarial loss	0	[2]	0	[2]
Net current-period other comprehensive income	0		0
Gain or Loss on Derivatives [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(718,000)
Other comprehensive income before reclassifications	0
Ending balance	(659,000)
Gain or Loss on Derivatives [Member] | Interest rate swaps
Accumulated Other Comprehensive Loss [Roll Forward]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	59,000	[1]
Gain or Loss on Derivatives [Member] | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Loss [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss, Actuarial loss	0	[2]
Net current-period other comprehensive income	59,000
Gain or Loss on Derivatives [Member] | Reclassification out of Accumulated Other Comprehensive Income | Interest rate swaps
Accumulated Other Comprehensive Loss [Roll Forward]
Amounts reclassified from accumulated other comprehensive loss, tax	$ 37,000

[1] (a) Included in interest expense in the Condensed Consolidated Statements of Operations

[2] (b) Included in defined benefit pension plan expense in the Condensed Consolidated Statements of Operations