Income Taxes (Details 6) (USD $)	Dec. 31, 2014
Operating Loss Carryforwards
Deferred tax asset relating to NOL carryforwards that have an indefinite life	$ 1,430,000,000
Recognized valuation allowance relating to NOL carryforwards	1,430,000,000
Operating Loss Carryforwards
Expiring NOLs	595,004,000
Non-expiring NOLs	4,898,787,000
Total	5,493,791,000
2015
Operating Loss Carryforwards
Expiring NOLs	8,295,000
2016
Operating Loss Carryforwards
Expiring NOLs	27,847,000
2017
Operating Loss Carryforwards
Expiring NOLs	34,729,000
2018
Operating Loss Carryforwards
Expiring NOLs	48,559,000
2019
Operating Loss Carryforwards
Expiring NOLs	15,997,000
2020
Operating Loss Carryforwards
Expiring NOLs	15,115,000
2021
Operating Loss Carryforwards
Expiring NOLs	21,354,000
2022
Operating Loss Carryforwards
Expiring NOLs	1,282,000
2023
Operating Loss Carryforwards
Expiring NOLs	2,965,000
2024
Operating Loss Carryforwards
Expiring NOLs	7,583,000
2028
Operating Loss Carryforwards
Expiring NOLs	8,000
2030
Operating Loss Carryforwards
Expiring NOLs	99,000
2031
Operating Loss Carryforwards
Expiring NOLs	242,703,000
2032
Operating Loss Carryforwards
Expiring NOLs	75,257,000
2033
Operating Loss Carryforwards
Expiring NOLs	83,601,000
2034
Operating Loss Carryforwards
Expiring NOLs	9,610,000
Internal Revenue Service (IRS)
Operating Loss Carryforwards
Expiring NOLs	214,281,000
Total	214,281,000
Internal Revenue Service (IRS) | 2019
Operating Loss Carryforwards
Expiring NOLs	13,369,000
Internal Revenue Service (IRS) | 2031
Operating Loss Carryforwards
Expiring NOLs	200,912,000
Mexico
Operating Loss Carryforwards
Expiring NOLs	380,723,000
Non-expiring NOLs	4,898,787,000
Total	5,279,510,000
Mexico | 2015
Operating Loss Carryforwards
Expiring NOLs	8,295,000
Mexico | 2016
Operating Loss Carryforwards
Expiring NOLs	27,847,000
Mexico | 2017
Operating Loss Carryforwards
Expiring NOLs	34,729,000
Mexico | 2018
Operating Loss Carryforwards
Expiring NOLs	48,559,000
Mexico | 2019
Operating Loss Carryforwards
Expiring NOLs	2,628,000
Mexico | 2020
Operating Loss Carryforwards
Expiring NOLs	15,115,000
Mexico | 2021
Operating Loss Carryforwards
Expiring NOLs	21,354,000
Mexico | 2022
Operating Loss Carryforwards
Expiring NOLs	1,282,000
Mexico | 2023
Operating Loss Carryforwards
Expiring NOLs	2,965,000
Mexico | 2024
Operating Loss Carryforwards
Expiring NOLs	7,583,000
Mexico | 2028
Operating Loss Carryforwards
Expiring NOLs	8,000
Mexico | 2030
Operating Loss Carryforwards
Expiring NOLs	99,000
Mexico | 2031
Operating Loss Carryforwards
Expiring NOLs	41,791,000
Mexico | 2032
Operating Loss Carryforwards
Expiring NOLs	75,257,000
Mexico | 2033
Operating Loss Carryforwards
Expiring NOLs	83,601,000
Mexico | 2034
Operating Loss Carryforwards
Expiring NOLs	9,610,000
State and Local Jurisdiction
Operating Loss Carryforwards
NOL carryforwards for alternative minimum tax purpose	192,000,000
State and Local Jurisdiction | 2015-2034
Operating Loss Carryforwards
NOL carryforwards for alternative minimum tax purpose	$ 313,000,000