Reconciliation of Segment Operating Income (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Notes to Financial Statements
Total operating income									$ 5,360,520	$ 4,284,964
Interest expense, net									264,398	254,565
Other expense, net									99,076	4,379
Consolidated income before taxes									4,997,046	4,026,020
Net income	$ 430,000	$ 798,000	$ 2,061,000	$ 260,000	$ 266,000	$ 682,000	$ 1,743,000	$ 120,000	$ 3,549,231	$ 2,811,193