Fair Value Measurements (Details) (USD $)	12 Months Ended		12 Months Ended
	Dec. 31, 2012 Allied Transportation Company [Member]	Nov. 01, 2012 Allied Transportation Company [Member]	Dec. 31, 2011 United Holdings Llc [Member]	Dec. 31, 2012 United Holdings Llc [Member]	Apr. 15, 2011 United Holdings Llc [Member]	Dec. 31, 2012 Recurring [Member]	Dec. 31, 2011 Recurring [Member]	Dec. 31, 2012 Quoted Prices In Active Markets For Identical Assets (Level 1) Recurring [Member]	Dec. 31, 2011 Quoted Prices In Active Markets For Identical Assets (Level 1) Recurring [Member]	Dec. 31, 2012 Significant Other Observable Inputs (Level 2) Recurring [Member]	Dec. 31, 2011 Significant Other Observable Inputs (Level 2) Recurring [Member]	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Recurring [Member]	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Recurring [Member]
Assets [Abstract]
Derivatives						$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0
Liabilities [Abstract]
Derivatives						1,525,000	9,597,000	0	0	1,525,000	9,597,000	0	0
Contingent earnout liability						28,067,000	22,600,000	0	0	0	0	28,067,000	22,600,000
Liabilities fair value						29,592,000	32,197,000	0	0	1,525,000	9,597,000	28,067,000	22,600,000
Business Acquisition [Line Items]
Earnout Provision		10,000,000			50,000,000
Fair value contingent earnout liability	9,767,000	9,756,000	22,600,000	18,300,000	16,300,000
Increase (decrease) in fair value of earnout liablity	$ 11,000		$ 4,300,000