Concentration of Credit Risk (Tables)

12 Months Ended

Dec. 31, 2012

Concentration of Credit Risk [Abstract]

Future minimum lease payments receivable under noncancelable leases

As of December 31, 2012, minimum future lease revenue payments receivable under noncancelable leases were as follows:

	Operating		Finance
Years ending	leases		leases
2013	$	16,916,900	$	296,700
2014		10,941,200		84,000
2015		6,747,000		84,000
2016		5,389,200		84,000
2017 and thereafter		2,728,300		73,500
	$	42,722,600	$	622,200