Related Party Transactions (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transactions
Length of motorsports superspeedway of entity (in miles)	1
Dover facility
Related Party Transactions
Costs for administrative and operating services, including leased space allocated by related party	$ 804,000	$ 855,000	$ 928,000
Administrative and operating service costs allocated to related party	381,000	397,000	353,000
Dover Downs Gaming & Entertainment, Inc
Related Party Transactions
Costs for administrative and operating services, including leased space allocated by related party	1,865,000	1,963,000	1,977,000
Administrative and operating service costs allocated to related party	$ 217,000	$ 347,000	$ 222,000
Length of harness racing track used (in miles)	0.625
Period, before and after the period of exclusive use of harness track, for which related party has set up and tear down rights (in weeks)	2
Number of annual motorsports weekends for which use of indoor grandstands is allowed by related party	2
Dover Downs Gaming & Entertainment, Inc | Transition Support Services Agreement
Related Party Transactions
Number of business days after receipt of an invoice within which the party receiving the services is required to pay	30
Period within which the agreement may be terminated after the request of the party receiving the services	90 days
Period within which the agreement may be terminated after the request of the party providing the services	180 days
Henry B. Tippie
Related Party Transactions
Minimum percentage of voting power controlled by related party	50.00%
Minimum percentage of voting power of Gaming controlled by other related party	50.00%
DDE | Various agreements
Related Party Transactions
Number of companies between which assets and liabilities are allocated	2