Fair Value Measurements - Summary of Carrying Amount and Fair Value of Ambac's Financial Assets and Liabilities (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	$ 3,476,694,000
Financial assets:
Short term investments	664,441,000	$ 430,331,000
Other investments	462,427,000	391,217,000
Derivative assets	82,230,000	59,768,000
Other assets	3,388,000	4,516,000
Long-term Debt	2,954,929,000	2,928,929,000
Financial liabilities:
Derivative liabilities	103,382,000	76,999,000
Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	3,158,608,000	2,737,286,000
Financial assets:
Loans	2,965,539,000	4,287,664,000
Derivative assets	67,921,000	66,302,000
Long-term Debt	4,353,171,000	5,268,596,000
Financial liabilities:
Derivative liabilities	1,779,077,000	1,712,062,000
Long-term debt	4,151,433,000	5,268,596,000
Short-term Investments [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	664,441,000	430,331,000
Corporate Debt Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	2,995,894,000	2,737,286,000
Municipal Bonds [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	162,714,000	0
Total Fair Value [Member]
Financial assets:
Cash	64,512,000	82,494,000
Reported Value Measurement [Member]
Financial assets:
Cash	64,512,000	82,494,000
Loans	9,770,000	9,913,000
Other assets	3,388,000	4,516,000
Total financial assets	10,294,189,000	11,185,865,000
Financial liabilities:
Liabilities for net financial guarantees written	(932,517,000)	(718,388,000)
Long-term debt	3,378,744,000	3,304,737,000
Total financial liabilities	8,681,789,000	9,643,706,000
Reported Value Measurement [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Restricted Cash and Cash Equivalents, Current	3,168,000	999,000
Loans	2,965,539,000	4,287,664,000
Financial liabilities:
Long-term debt	4,353,171,000	5,268,596,000
Reported Value Measurement [Member] | Short-term Investments [Member]
Financial assets:
Short term investments	664,441,000	430,331,000
Reported Value Measurement [Member] | Other Debt Obligations [Member]
Financial assets:
Other investments	462,427,000	391,217,000
Reported Value Measurement [Member] | Corporate Debt Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	2,995,894,000	2,737,286,000
Reported Value Measurement [Member] | Municipal Bonds [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	162,714,000
Reported Value Measurement [Member] | Future [Member]
Financial assets:
Derivative assets	393,000
Financial liabilities:
Derivative liabilities		3,379,000
Reported Value Measurement [Member] | Interest Rate Swap [Member]
Financial liabilities:
Derivative liabilities - interest rate swaps - asset position	68,000
Derivative liabilities	102,960,000	71,861,000
Reported Value Measurement [Member] | Interest Rate Swap [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial liabilities:
Derivative liabilities	1,779,077,000	1,712,062,000
Reported Value Measurement [Member] | Currency Swaps [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Derivative assets	67,921,000	66,302,000
Reported Value Measurement [Member] | Other Credit Derivatives [Member]
Financial liabilities:
Derivative liabilities	422,000	1,459,000
Other Assets [Member] | Reported Value Measurement [Member] | Interest Rate Swap [Member]
Financial assets:
Derivative assets	81,769,000	59,468,000
Level 1 [Member]
Financial assets:
Cash	30,596,000	52,661,000
Total financial assets	1,052,281,000	553,964,000
Financial liabilities:
Liabilities for net financial guarantees written	0	0
Long-term debt	0	0
Total financial liabilities	0	3,379,000
Level 1 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Restricted Cash and Cash Equivalents, Current	3,168,000	999,000
Loans	0	0
Financial liabilities:
Long-term debt	0	0
Level 1 [Member] | Short-term Investments [Member]
Financial assets:
Short term investments	603,435,000	304,880,000
Level 1 [Member] | Equity Method Investments [Member]
Financial assets:
Other assets	0	0
Level 1 [Member] | Loans Receivable [Member]
Financial assets:
Loans	0	0
Level 1 [Member] | Other Debt Obligations [Member]
Financial assets:
Other investments	130,393,000	71,108,000
Level 1 [Member] | Corporate Debt Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Level 1 [Member] | Municipal Bonds [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0
Level 1 [Member] | Future [Member]
Financial assets:
Derivative assets	393,000
Financial liabilities:
Derivative liabilities		3,379,000
Level 1 [Member] | Interest Rate Swap [Member]
Financial liabilities:
Derivative liabilities - interest rate swaps - asset position	0
Derivative liabilities	0	0
Level 1 [Member] | Interest Rate Swap [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial liabilities:
Derivative liabilities	0	0
Level 1 [Member] | Currency Swaps [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Derivative assets	0	0
Level 1 [Member] | Other Credit Derivatives [Member]
Financial liabilities:
Derivative liabilities	0	0
Level 1 [Member] | Other Assets [Member] | Interest Rate Swap [Member]
Financial assets:
Derivative assets	0	0
Level 2 [Member]
Financial assets:
Cash	33,916,000	29,833,000
Total financial assets	2,782,710,000	3,152,882,000
Financial liabilities:
Liabilities for net financial guarantees written	0	0
Long-term debt	2,965,844,000	2,909,272,000
Total financial liabilities	9,055,920,000	9,744,699,000
Level 2 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Restricted Cash and Cash Equivalents, Current	0	0
Loans	0	0
Financial liabilities:
Long-term debt	4,208,107,000	5,051,504,000
Level 2 [Member] | Short-term Investments [Member]
Financial assets:
Short term investments	61,006,000	125,451,000
Level 2 [Member] | Equity Method Investments [Member]
Financial assets:
Other assets	0	0
Level 2 [Member] | Loans Receivable [Member]
Financial assets:
Loans	0	0
Level 2 [Member] | Other Debt Obligations [Member]
Financial assets:
Other investments	0	0
Level 2 [Member] | Corporate Debt Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Level 2 [Member] | Municipal Bonds [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	162,714,000
Level 2 [Member] | Future [Member]
Financial assets:
Derivative assets	0
Financial liabilities:
Derivative liabilities		0
Level 2 [Member] | Interest Rate Swap [Member]
Financial liabilities:
Derivative liabilities - interest rate swaps - asset position	68,000
Derivative liabilities	102,960,000	71,861,000
Level 2 [Member] | Interest Rate Swap [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial liabilities:
Derivative liabilities	1,779,077,000	1,712,062,000
Level 2 [Member] | Currency Swaps [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Derivative assets	67,921,000	66,302,000
Level 2 [Member] | Other Credit Derivatives [Member]
Financial liabilities:
Derivative liabilities	0	0
Level 2 [Member] | Other Assets [Member] | Interest Rate Swap [Member]
Financial assets:
Derivative assets	8,617,000	12,008,000
Level 3 [Member]
Financial assets:
Cash	0	0
Total financial assets	6,148,106,000	7,176,883,000
Financial liabilities:
Liabilities for net financial guarantees written	179,352,000	558,824,000
Long-term debt	398,936,000	350,694,000
Total financial liabilities	736,915,000	1,128,069,000
Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Restricted Cash and Cash Equivalents, Current	0	0
Loans	2,965,539,000	4,287,664,000
Financial liabilities:
Long-term debt	158,205,000	217,092,000
Level 3 [Member] | Short-term Investments [Member]
Financial assets:
Short term investments	0	0
Level 3 [Member] | Equity Method Investments [Member]
Financial assets:
Other assets	3,388,000	4,516,000
Level 3 [Member] | Loans Receivable [Member]
Financial assets:
Loans	13,032,000	11,620,000
Level 3 [Member] | Other Debt Obligations [Member]
Financial assets:
Other investments	17,680,000	16,266,000
Level 3 [Member] | Corporate Debt Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	2,995,894,000	2,737,286,000
Level 3 [Member] | Municipal Bonds [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0
Level 3 [Member] | Future [Member]
Financial assets:
Derivative assets	0
Financial liabilities:
Derivative liabilities
Level 3 [Member] | Interest Rate Swap [Member]
Financial liabilities:
Derivative liabilities - interest rate swaps - asset position	0
Derivative liabilities	0	0
Level 3 [Member] | Interest Rate Swap [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial liabilities:
Derivative liabilities	0	0
Level 3 [Member] | Currency Swaps [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Derivative assets	0	0
Level 3 [Member] | Other Credit Derivatives [Member]
Financial liabilities:
Derivative liabilities	422,000	1,459,000
Level 3 [Member] | Other Assets [Member] | Interest Rate Swap [Member]
Financial assets:
Derivative assets	73,152,000	47,460,000
Municipal Bonds [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	305,128,000	879,919,000
Corporate Debt Securities [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	1,469,250,000	1,278,122,000
Debt Security, Government, Non-US [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	42,488,000	30,834,000
US Government Debt Securities [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	156,060,000	94,394,000
Residential Mortgage-Backed Securities [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	257,340,000	258,607,000
Collateralized Debt Obligations [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	147,835,000	131,356,000
Asset-backed Securities [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	349,204,000	442,443,000
Fair Value, Recurring [Member]
Financial assets:
Total financial assets	10,270,844,000	11,163,670,000
Financial liabilities:
Liabilities for net financial guarantees written	179,352,000	558,824,000
Long-term debt	3,364,780,000	3,259,966,000
Total financial liabilities	9,792,835,000	10,876,147,000
Fair Value, Recurring [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Restricted Cash and Cash Equivalents, Current	3,168,000	999,000
Loans	2,965,539,000	4,287,664,000
Financial liabilities:
Long-term debt	4,366,312,000	5,268,596,000
Fair Value, Recurring [Member] | Short-term Investments [Member]
Financial assets:
Short term investments	664,441,000	430,331,000
Fair Value, Recurring [Member] | Equity Method Investments [Member]
Financial assets:
Other assets	3,388,000	4,516,000
Fair Value, Recurring [Member] | Loans Receivable [Member]
Financial assets:
Loans	13,032,000	11,620,000
Fair Value, Recurring [Member] | Other Debt Obligations [Member]
Financial assets:
Other investments	435,820,000	367,315,000
Fair Value, Recurring [Member] | Asset-backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	349,204,000	442,443,000
Fair Value, Recurring [Member] | Collateralized Debt Obligations [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	147,835,000	131,356,000
Fair Value, Recurring [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	257,340,000	258,607,000
Fair Value, Recurring [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	156,060,000	94,394,000
Fair Value, Recurring [Member] | Debt Security, Government, Non-US [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	42,488,000	30,834,000
Fair Value, Recurring [Member] | Corporate Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	1,469,250,000	1,278,122,000
Fair Value, Recurring [Member] | Corporate Debt Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	2,995,894,000	2,737,286,000
Fair Value, Recurring [Member] | Municipal Bonds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	305,128,000	879,919,000
Fair Value, Recurring [Member] | Municipal Bonds [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	162,714,000
Fair Value, Recurring [Member] | Future [Member]
Financial assets:
Derivative assets	393,000
Financial liabilities:
Derivative liabilities		3,379,000
Fair Value, Recurring [Member] | Interest Rate Swap [Member]
Financial liabilities:
Derivative liabilities - interest rate swaps - asset position	68,000
Derivative liabilities	102,960,000	71,861,000
Fair Value, Recurring [Member] | Interest Rate Swap [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial liabilities:
Derivative liabilities	1,779,077,000	1,712,062,000
Fair Value, Recurring [Member] | Currency Swaps [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial assets:
Derivative assets	67,921,000	66,302,000
Fair Value, Recurring [Member] | Other Credit Derivatives [Member]
Financial liabilities:
Derivative liabilities	422,000	1,459,000
Fair Value, Recurring [Member] | Other Assets [Member] | Interest Rate Swap [Member]
Financial assets:
Derivative assets	81,769,000	59,468,000
Fair Value, Recurring [Member] | Level 1 [Member] | Asset-backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Collateralized Debt Obligations [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 1 [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	156,060,000	94,394,000
Fair Value, Recurring [Member] | Level 1 [Member] | Debt Security, Government, Non-US [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	42,488,000	29,922,000
Fair Value, Recurring [Member] | Level 1 [Member] | Corporate Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	800,000	0
Fair Value, Recurring [Member] | Level 1 [Member] | Municipal Bonds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 2 [Member] | Asset-backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	269,783,000	370,372,000
Fair Value, Recurring [Member] | Level 2 [Member] | Collateralized Debt Obligations [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	147,835,000	131,356,000
Fair Value, Recurring [Member] | Level 2 [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	257,340,000	258,607,000
Fair Value, Recurring [Member] | Level 2 [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 2 [Member] | Debt Security, Government, Non-US [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	912,000
Fair Value, Recurring [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	1,468,450,000	1,278,122,000
Fair Value, Recurring [Member] | Level 2 [Member] | Municipal Bonds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	305,128,000	879,919,000
Fair Value, Recurring [Member] | Level 3 [Member] | Asset-backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	79,421,000	72,071,000
Fair Value, Recurring [Member] | Level 3 [Member] | Collateralized Debt Obligations [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 3 [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Debt Security, Government, Non-US [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Corporate Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Municipal Bonds [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0	$ 0
Collateral Pledged [Member] | US Government Debt Securities [Member] | Reported Value Measurement [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	84,948,000
Collateral Pledged [Member] | Fair Value, Recurring [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	84,948,000
Collateral Pledged [Member] | Fair Value, Recurring [Member] | Level 1 [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	84,948,000
Collateral Pledged [Member] | Fair Value, Recurring [Member] | Level 2 [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	0
Collateral Pledged [Member] | Fair Value, Recurring [Member] | Level 3 [Member] | US Government Debt Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fixed income securities, at fair value (amortized cost of $2,561,278 and $3,020,744)	$ 0