Multiemployer Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Multiemployer Plans [Line Items]
Multiemployer Plans Period Contributions Significance Of Contributions	false
Multiemployer Pension Plans [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Period Contributions	$ 196	$ 215	$ 229
Multiemployer plan period contributions from continuing operations	135	140	149
Multiemployer Health Plans [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Period Contributions	734	731	735
Multiemployer plan period contributions from continuing operations	$ 484	$ 480	$ 510