Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Identifiable Intangible Assets (Details) - Investment Advisory Contract [Member] - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Gabelli Enterprise Mergers and Acquisitions Fund [Member]
Finite-Lived Intangible Assets [Line Items]
Identifiable intangible asset	$ 1.9	$ 1.9	$ 1.9
Bancroft Fund Ltd. and the Ellsworth Growth and Income Fund Ltd. [Member]
Finite-Lived Intangible Assets [Line Items]
Identifiable intangible asset	$ 1.6	$ 1.6