Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2013
Minimum
Restricted Cash
Threshold period for project completion for which restricted cash is held to classify as long-term asset	12 months
Property, Plant and Equipment
Threshold relocation cost of tangible assets as percentage of fair value to be classified as real estate (as a percent)	10.00%
Property, plant and equipment other than miscellaneous equipment and vehicles | Minimum
Property, Plant and Equipment
Estimated useful lives of assets	10 years
Property, plant and equipment other than miscellaneous equipment and vehicles | Maximum
Property, Plant and Equipment
Estimated useful lives of assets	25 years
Miscellaneous equipment and vehicles | Minimum
Property, Plant and Equipment
Estimated useful lives of assets	3 years
Miscellaneous equipment and vehicles | Maximum
Property, Plant and Equipment
Estimated useful lives of assets	10 years