Debt and Notes Payable (Detail Textuals) (U. S. Credit Agreement)	12 Months Ended
	Dec. 31, 2012
U. S. Credit Agreement
Debt Instrument [Line Items]
Agreement covenants ratio of cash flow to debt service on a rolling four quarter basis	1.25 to 1.0
Cash flow to debt service ratio	5.70 to 1.0