Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended											6 Months Ended		12 Months Ended	6 Months Ended		12 Months Ended	6 Months Ended		12 Months Ended	6 Months Ended		12 Months Ended	6 Months Ended		12 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2014 Convertible Preferred Stock		Mar. 31, 2014 Convertible Preferred Stock		Jun. 30, 2013 Convertible Preferred Stock		Mar. 31, 2013 Convertible Preferred Stock		Jun. 30, 2014 Level 3 Convertible Preferred Stock	Dec. 31, 2013 Level 3 Convertible Preferred Stock	Jun. 30, 2013 Level 3 Convertible Preferred Stock	Jun. 30, 2014 Income Approach Valuation Technique Level 3 Convertible Preferred Stock	Jun. 30, 2013 Income Approach Valuation Technique Level 3 Convertible Preferred Stock	Dec. 31, 2013 Income Approach Valuation Technique Level 3 Convertible Preferred Stock	Jun. 30, 2014 Income Approach Valuation Technique Maximum Level 3 Convertible Preferred Stock	Jun. 30, 2013 Income Approach Valuation Technique Maximum Level 3 Convertible Preferred Stock	Dec. 31, 2013 Income Approach Valuation Technique Maximum Level 3 Convertible Preferred Stock	Jun. 30, 2014 Income Approach Valuation Technique Minimum Level 3 Convertible Preferred Stock	Jun. 30, 2013 Income Approach Valuation Technique Minimum Level 3 Convertible Preferred Stock	Dec. 31, 2013 Income Approach Valuation Technique Minimum Level 3 Convertible Preferred Stock	Jun. 30, 2014 Market Approach Valuation Technique Level 3 Convertible Preferred Stock	Jun. 30, 2013 Market Approach Valuation Technique Level 3 Convertible Preferred Stock	Dec. 31, 2013 Market Approach Valuation Technique Level 3 Convertible Preferred Stock	Jun. 30, 2014 Market Approach Valuation Technique Maximum Level 3 Convertible Preferred Stock	Jun. 30, 2013 Market Approach Valuation Technique Maximum Level 3 Convertible Preferred Stock	Dec. 31, 2013 Market Approach Valuation Technique Maximum Level 3 Convertible Preferred Stock	Jun. 30, 2014 Market Approach Valuation Technique Minimum Level 3 Convertible Preferred Stock	Jun. 30, 2013 Market Approach Valuation Technique Minimum Level 3 Convertible Preferred Stock	Dec. 31, 2013 Market Approach Valuation Technique Minimum Level 3 Convertible Preferred Stock
Fair Value Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple																					7.75	6.60	7.75	8.00	7.00	8.00	7.50	5.50	7.50
Beginning and ending balances for the Company's fair value measurements using Level 3 inputs
Asset, Beginning Balance	$ 20,530		$ 25,720		$ 17,710		$ 17,220		$ 16,950	$ 25,720	$ 17,710
Unrealized gains (losses) included in other comprehensive income	(3,580)	[1]	(5,190)	[1]	0	[1]	490	[1]
Asset, Ending Balance	$ 16,950		$ 20,530		$ 17,710		$ 17,710		$ 16,950	$ 25,720	$ 17,710
Fair Value Inputs, Discount Rate												14.50%	17.00%	14.50%	14.50%	17.00%	14.50%	14.50%	17.00%	14.50%

[1] (a) The decrease in value from year end is due to reductions in forecasted traffic on the railroad