Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 11, 2013
Income Tax Disclosure [Line Items]
Amount the Company's book basis exceeded the tax basis of its foreign investments	$ 1,593.9
Gross federal income taxes the Company would incur if the earnings were to be remitted in a taxable transaction	557.9
Statutory income tax rate	35.00%	35.00%	35.00%
NAFTA [Member]
Income Tax Disclosure [Line Items]
Value added tax receivable, noncurrent	13.4
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforward, amount	472.5
State and Local Jurisdiction [Member] | Maximum [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforward, period	20 years
State and Local Jurisdiction [Member] | Minimum [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforward, period	5 years
Mexican Tax Authority [Member] | Foreign Tax Authority [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforward, amount	83.5
Tax credit carryforward, amount	5.7
Mexican Tax Authority [Member] | Foreign Tax Authority [Member] | Eliminated 2014 Tax Rate Reduction [Member]
Income Tax Disclosure [Line Items]
Statutory income tax rate				29.00%
Mexican Tax Authority [Member] | Foreign Tax Authority [Member] | Eliminated 2015 Tax Rate Reduction [Member]
Income Tax Disclosure [Line Items]
Statutory income tax rate				28.00%
Mexican Tax Authority [Member] | Foreign Tax Authority [Member] | Years 2013 And Forward [Member]
Income Tax Disclosure [Line Items]
Statutory income tax rate				30.00%
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforward, amount	32.8
Federal operating loss carryforward not recognized in the financial statements	8.9
Tax credit carryforward, amount	37.3
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member] | Track Maintenance Credits [Member]
Income Tax Disclosure [Line Items]
Tax credit carryforward, amount	$ 31.7
Internal Revenue Service (IRS) [Member] | Domestic Tax Authority [Member] | Maximum [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforward, period	20 years