Leasing Activities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015 Restaurants	Mar. 31, 2014 Restaurants
Operating Leased Assets [Line Items]
Number of restaurants leased to Del Taco	6	6
Number of properties subleased to Del Taco franchisee	1
Number of lease years	35 years
Percentage of gross sales of restaurants	12.00%
Leases expiration period	2020 to 2021
Minimum rentals due to partnership	$ 3,500
Number of restaurants operated	5
Combined unaudited sales	1,504,262	1,360,037
Combined unaudited net income (losses)	31,680	(11,733)
Del Taco franchisee [Member]
Operating Leased Assets [Line Items]
Number of restaurants operated	1
Combined unaudited sales	$ 241,156	$ 220,788