Credit Facilities and Long-Term Debt (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Summary of outstanding long-term debt balances
Total notes payable	$ 43,955,074	$ 44,334,240
Less: current portion	506,522	633,498
Notes payable, long-term portion	43,448,552	43,700,742
LIBOR plus 1.75 to 2.25%, Bank of America amortizing term loan, due April 1, 2017 [Member]
Summary of outstanding long-term debt balances
Total notes payable	9,625,000	10,000,000
6.16%, Senior unsecured notes, due June 29, 2017 [Member]
Summary of outstanding long-term debt balances
Total notes payable	13,000,000	13,000,000
5.38%, Sun Life fixed rate note, due June 1, 2017 [Member]
Summary of outstanding long-term debt balances
Total notes payable	15,334,000	15,334,000
LIBOR plus 3.85%, Sun Life floating rate note, due May 3, 2014 [Member]
Summary of outstanding long-term debt balances
Total notes payable	3,000,000	3,000,000
4.15% Sun Life senior secured guaranteed note, due June 1, 2017 [Member]
Summary of outstanding long-term debt balances
Total notes payable	2,989,552	2,989,552
Vehicle loan [Member]
Summary of outstanding long-term debt balances
Total notes payable	$ 6,522	$ 10,688