Fair Value of Financial Instruments Fair value measurement (Details) (USD $) | Oct. 15, 2013 | Sep. 30, 2013 | Dec. 31, 2012 | Jan. 23, 2004 |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | $65,275,000 | $79,534,000 | ' |
Available-for-sale Securities, Debt Securities | ' | 65,275,000 | 79,534,000 | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 16,523,000 | 3,548,000 | ' |
Other Investments | ' | 3,107,000 | 2,000,000 | ' |
Short-term investments, at cost which approximates fair value | ' | 586,000 | 585,000 | ' |
Investments | ' | 88,070,000 | 88,000,000 | ' |
Assets | ' | 345,366,000 | 372,800,000 | ' |
LROC preferred units | ' | 14,286,000 | 13,655,000 | ' |
Senior unsecured debentures | 14,400,000 | 26,356,000 | 23,730,000 | 125,000,000 |
Subordinated debt | ' | 22,790,000 | 23,774,000 | ' |
Long-term Debt | ' | 63,432,000 | 61,159,000 | ' |
Fair Value, Inputs Level 1, Preferred Stock [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 0 | ' | ' |
Fair Value, Inputs Level 1, Common Stock [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 16,523,000 | ' | ' |
Fair Value, Inputs Level 2, Common Stock [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 0 | ' | ' |
US Government Agencies Debt Securities [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 25,338,000 | 24,915,000 | ' |
Foreign Government Debt Securities [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 4,242,000 | 3,782,000 | ' |
Fair Value, Inputs, Level 1 [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 16,523,000 | ' | ' |
Available-for-sale Securities, Debt Securities | ' | 0 | 0 | ' |
Financial Instruments, Owned, Corporate Debt, at Fair Value | ' | 0 | 0 | ' |
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure | ' | 0 | 0 | ' |
Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value | ' | 0 | 0 | ' |
Municipal Debt Securities, at Carrying Value | ' | 0 | 0 | ' |
Financial Instruments, Owned, Other Sovereign Government Obligations, at Fair Value | ' | 0 | 0 | ' |
Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value | ' | 0 | 0 | ' |
Other Investments | ' | 0 | 0 | ' |
Short-term investments, at cost which approximates fair value | ' | 0 | 0 | ' |
Assets | ' | 16,523,000 | 3,548,000 | ' |
Senior unsecured debentures | ' | 0 | 0 | ' |
Subordinated debt | ' | 0 | 0 | ' |
Long-term Debt | ' | 14,286,000 | 13,655,000 | ' |
Fair Value, Inputs, Level 2 [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Debt Securities | ' | 65,275,000 | 79,534,000 | ' |
Financial Instruments, Owned, Corporate Debt, at Fair Value | ' | 27,393,000 | 37,357,000 | ' |
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure | ' | 736,000 | 5,043,000 | ' |
Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value | ' | 319,000 | 1,092,000 | ' |
Municipal Debt Securities, at Carrying Value | ' | 7,247,000 | 7,345,000 | ' |
Financial Instruments, Owned, Other Sovereign Government Obligations, at Fair Value | ' | 4,242,000 | 3,782,000 | ' |
Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value | ' | 25,338,000 | 24,915,000 | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 0 | 0 | ' |
Assets | ' | 68,968,000 | 82,119,000 | ' |
LROC preferred units | ' | 0 | 0 | ' |
Long-term Debt | ' | 49,146,000 | 47,504,000 | ' |
Fair Value, Inputs, Level 3 [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Debt Securities | ' | 0 | 0 | ' |
Financial Instruments, Owned, Corporate Debt, at Fair Value | ' | 0 | 0 | ' |
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure | ' | 0 | 0 | ' |
Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, at Fair Value | ' | 0 | 0 | ' |
Municipal Debt Securities, at Carrying Value | ' | 0 | 0 | ' |
Financial Instruments, Owned, Other Sovereign Government Obligations, at Fair Value | ' | 0 | 0 | ' |
Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value | ' | 0 | 0 | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 0 | 0 | ' |
Other Investments | ' | 0 | 0 | ' |
Short-term investments, at cost which approximates fair value | ' | 0 | 0 | ' |
Assets | ' | 0 | 0 | ' |
LROC preferred units | ' | 0 | 0 | ' |
Senior unsecured debentures | ' | 0 | 0 | ' |
Subordinated debt | ' | 0 | 0 | ' |
Long-term Debt | ' | 0 | 0 | ' |
Equity Securities [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 16,523,000 | ' | ' |
Preferred Stock [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 0 | ' | ' |
Common Stock [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Equity investments, at fair value (cost of $11,520 and $2,305, respectively) | ' | 16,523,000 | 3,548,000 | ' |
Summary of Investments, by Type [Domain] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Investments | ' | 85,491,000 | 85,667,000 | ' |
Debt, State Government [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 7,247,000 | 7,345,000 | ' |
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 736,000 | 5,043,000 | ' |
Asset-backed Securities [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 319,000 | 1,092,000 | ' |
Corporate Debt Securities [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities | ' | 27,393,000 | 37,357,000 | ' |
Other Investments [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Other Investments | ' | 3,107,000 | 2,000,000 | ' |
Short-term Investments [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Short-term investments, at cost which approximates fair value | ' | 586,000 | 585,000 | ' |
Debt Securities [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
LROC preferred units | ' | 14,286,000 | 13,655,000 | ' |
Senior Notes [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Senior unsecured debentures | ' | 26,356,000 | 23,730,000 | ' |
Subordinated Debt [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Subordinated debt | ' | 22,790,000 | 23,774,000 | ' |
Liability [Member] | ' | ' | ' | ' |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | ' | ' | ' | ' |
Long-term Debt | ' | $63,432,000 | $61,159,000 | ' |