CONDENSED BALANCE SHEETS [Parenthetical] (USD $)	Dec. 31, 2014	Mar. 31, 2014	Sep. 04, 1993
Beneficial assignee certificate, par value (in dollars per share)	$ 10	$ 10	$ 10
Units of limited partnership interest, authorized	22,000,000	22,000,000	20,000,000
Units of limited partnership interest, issued	21,996,102	21,996,102
Units of limited partnership interest, outstanding	21,937,787	21,981,089
Series Fifteen [Member]
Beneficial assignee certificate, par value (in dollars per share)	$ 10	$ 10
Units of limited partnership interest, authorized	22,000,000	22,000,000
Units of limited partnership interest, issued	3,870,500	3,870,500
Units of limited partnership interest, outstanding	3,858,400	3,865,900
Series Sixteen [Member]
Beneficial assignee certificate, par value (in dollars per share)	$ 10	$ 10
Units of limited partnership interest, authorized	22,000,000	22,000,000
Units of limited partnership interest, issued	5,429,402	5,429,402
Units of limited partnership interest, outstanding	5,412,800	5,423,102
Series Seventeen [Member]
Beneficial assignee certificate, par value (in dollars per share)	$ 10	$ 10
Units of limited partnership interest, authorized	22,000,000	22,000,000
Units of limited partnership interest, issued	5,000,000	5,000,000
Units of limited partnership interest, outstanding	4,980,687	4,995,887
Series Eighteen [Member]
Beneficial assignee certificate, par value (in dollars per share)	$ 10	$ 10
Units of limited partnership interest, authorized	22,000,000	22,000,000
Units of limited partnership interest, issued	3,616,200	3,616,200
Units of limited partnership interest, outstanding	3,612,200	3,616,200
Series Nineteen [Member]
Beneficial assignee certificate, par value (in dollars per share)	$ 10	$ 10
Units of limited partnership interest, authorized	22,000,000	22,000,000
Units of limited partnership interest, issued	4,080,000	4,080,000
Units of limited partnership interest, outstanding	4,073,700	4,080,000