Schedule II - Valuation and Qualifying Accounts: (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Cost Basis
Balance at beginning of year	$ 36,571,114	$ 34,341,820
Additions	1,829,221	2,229,294
Disposals	0	0
Balance at end of year	38,400,335	36,571,114
Accumulated depreciation
Balance at beginning of year	27,872,044	26,071,629
Depreciation	1,846,520	1,800,415
Disposals	0	0
Balance at end of year	$ 29,718,564	$ 27,872,044