Certain Relationships and Related Party Transactions (Certain Relationships and Related Party Transactions) (Details) - MGP and Affiliates - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Productions costs, amount	$ 889,600	$ 894,600
Productions costs, $ change	$ (5,000)
Productions costs, % change	(1.00%)
General and administrative costs, amount	$ 93,600	92,900
General and administrative costs, $ change	$ 700
General and administrative costs, % change	1.00%
Transportation fees
Related Party Transaction [Line Items]
Productions costs, amount	$ 292,000	236,900
Productions costs, $ change	$ 55,100
Productions costs, % change	23.00%
Supervision fees
Related Party Transaction [Line Items]
Productions costs, amount	$ 329,600	384,100
Productions costs, $ change	$ (54,500)
Productions costs, % change	(14.00%)
Administrative fees
Related Party Transaction [Line Items]
General and administrative costs, amount	$ 25,400	29,500
General and administrative costs, $ change	$ (4,100)
General and administrative costs, % change	(14.00%)
Direct costs
Related Party Transaction [Line Items]
Productions costs, amount	$ 268,000	273,600
Productions costs, $ change	$ (5,600)
Productions costs, % change	(2.00%)
General and administrative costs, amount	$ 68,200	$ 63,400
General and administrative costs, $ change	$ 4,800
General and administrative costs, % change	8.00%

DGOC Series 18B LP 10-K