Income Taxes Valuation allowance (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Net operating loss carryforwards	$ 364,200,000
Valuation allowance, amount	12,194,000	8,613,000
From [Member]
Net operating loss carryforwards, expiration date	Dec. 31, 2014
To [Member]
Net operating loss carryforwards, expiration date	Dec. 31, 2033
Short line tax credit [Member]
Tax credit carryforward	221,278,000	129,486,000
Short line tax credit [Member] | From [Member]
United States track maintenance credit carryforward, expiration date	Dec. 31, 2025	Dec. 31, 2025
Short line tax credit [Member] | To [Member]
Net operating loss carryforwards, expiration date		Dec. 31, 2032
United States track maintenance credit carryforward, expiration date	Dec. 31, 2033
Net operating losses [Member]
Valuation allowance, deferred tax asset, change in amount	1,617,000
foreign tax credits [Member]
Valuation allowance, deferred tax asset, change in amount	$ 1,964,000