Investments (Details 1) - USD ($)		Dec. 31, 2019	Dec. 31, 2018
U.S. Equity Cumulative Dividends Fund-Series 2027 [Member]
Offsetting of Derivative Assets
Gross Amounts of Recognized Assets		$ 35,875
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		35,875
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash Collateral Pledged	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount		35,875
Offsetting of Derivative Liabilities
Gross Amounts of Recognized Liabilities		(28,500)	(28,500)
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		(28,500)	28,500
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash collateral Pledged	[1]		28,500
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount		(20,500)
U.S. Equity Cumulative Dividends Fund-Series 2027 [Member] | Futures Contracts [Member]
Offsetting of Derivative Assets
Gross Amounts of Recognized Assets		35,875
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		35,875
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash Collateral Pledged	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount		35,875
Offsetting of Derivative Liabilities
Gross Amounts of Recognized Liabilities		(20,500)	(28,500)
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		(28,500)	(28,500)
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash collateral Pledged	[1]		28,500
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount		(28,500)
U.S. Equity Ex-Dividends Fund-Series 2027 [Member]
Offsetting of Derivative Assets
Gross Amounts of Recognized Assets		81,000	137,813
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		81,000	137,813
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash Collateral Pledged	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount		81,000	137,813
Offsetting of Derivative Liabilities
Gross Amounts of Recognized Liabilities		(7,000)
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		(7,000)
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash collateral Pledged	[1]	7,000
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount
U.S. Equity Ex-Dividends Fund-Series 2027 [Member] | Futures Contracts [Member]
Offsetting of Derivative Assets
Gross Amounts of Recognized Assets		81,000	137,813
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		81,000	137,813
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash Collateral Pledged	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount		81,000	137,813
Offsetting of Derivative Liabilities
Gross Amounts of Recognized Liabilities		(7,000)
Gross Amounts Offset in the Statements of Financial Condition
Net Amounts Presented in the Statements of Financial Condition		(7,000)
Gross Amounts Not Offset in the Statements of Financial Condition, Financial Instruments	[1]
Gross Amounts Not Offset in the Statements of Financial Condition, Cash collateral Pledged	[1]	7,000
Gross Amounts Not Offset in the Statements of Financial Condition, Net Amount

[1] These amounts are limited to the derivatives asset/liability balance and, accordingly, do not include excess collateral received/pledged.