Significant Accounting Policies (Depreciation of Assets Based on Usage) (Details)	12 Months Ended
	Dec. 31, 2017
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Depreciation rate	10.00%
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Fixed assets useful life	15 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Fixed assets useful life	30 years
Yard Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Depreciation rate	20.00%
Yard Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Depreciation rate	30.00%
Automotive Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation rate	30.00%
Computer Software and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Fixed assets useful life	3 years
Computer Software and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Fixed assets useful life	5 years
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation rate	20.00%