Long Term Debt (Details Textual) (USD $)	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 23, 2011
Long Term Debt (Textual) [Abstract]
Total long-term debt	$ 116,951,000	$ 118,481,000
5.68% note, due June 30, 2026 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	29,000,000	29,000,000	29,000,000
Principal payments	2,900,000
Rate of unsecured senior loans			5.68%
Debt Instrument, Maturity Date	Jun. 30, 2026
9.57% bond, due May 1, 2018 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	5,442,000	6,348,000
Rate of unsecured senior loans	9.57%
Debt Instrument, Maturity Date	May 01, 2018
10.03% bond, due May 1, 2018 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	2,993,000	3,492,000
Rate of unsecured senior loans	10.03%
Debt Instrument, Maturity Date	May 01, 2018
9.08% bond, due June 1, 2022 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	7,960,000	7,958,000
Rate of unsecured senior loans	9.08%
Debt Instrument, Maturity Date	Jun. 01, 2022
7.83% note, due January 1, 2015 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	6,000,000	6,000,000
Rate of unsecured senior loans	7.83%
Debt Instrument, Maturity Date	Jan. 01, 2015
6.64% note, due October 31, 2017 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	16,363,000	16,363,000
Rate of unsecured senior loans	6.64%
Debt Instrument, Maturity Date	Oct. 31, 2017
5.50% note, due October 12, 2020 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	18,000,000	18,000,000
Rate of unsecured senior loans	5.50%
Debt Instrument, Maturity Date	Oct. 12, 2020
5.93% note, due October 31, 2023 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	30,000,000	30,000,000
Rate of unsecured senior loans	5.93%
Debt Instrument, Maturity Date	Oct. 31, 2023
8.25% due March 1, 2014 [Member]
Long Term Debt (Textual) [Abstract]
Total long-term debt	1,038,000	1,134,000
Rate of unsecured senior loans	8.25%
Debt Instrument, Maturity Date	Mar. 01, 2014
Unsecured Senior Notes [Member]
Long Term Debt (Textual) [Abstract]
Unsecured senior notes issue	$ 7,000,000
Unsecured Senior Notes [Member] | Maximum [Member]
Long Term Debt (Textual) [Abstract]
Rate of unsecured senior loans	6.43%
Unsecured Senior Notes [Member] | Minimum [Member]
Long Term Debt (Textual) [Abstract]
Rate of unsecured senior loans	5.28%
First Mortgage Bond One [Member]
Long Term Debt (Textual) [Abstract]
Rate of unsecured senior loans			6.85%
First Mortgage Bond Two [Member]
Long Term Debt (Textual) [Abstract]
Rate of unsecured senior loans			4.90%