Deferred drydock costs (Tables)

12 Months Ended

Dec. 31, 2012

Derivative Instruments and Fair Value Measurements [Abstract]

Schedule of Dry Docking Activity [Table Text Block]

Drydocking activity for the three years ended December 31, 2012 is summarized as follows:

	2012			2011			2010
Balance at January 1	$	3,303,363		$	4,217,071		$	5,266,289
Payments for drydocking		1,094,325			2,809,406			2,827,534
Drydock amortization		(2,265,309	)		(3,196,984	)		(3,441,583	)
Amount expensed upon sale of vessel		—			(526,130	)		(435,169	)
Balance at December 31	$	2,132,379		$	3,303,363		$	4,217,071