Merger Agreement - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended					3 Months Ended
	Dec. 31, 2012	Dec. 14, 2012	Nov. 30, 2012	Nov. 12, 2012	Nov. 30, 2011	Dec. 31, 2012 Merger related transaction costs [Member]
Merger Transaction [Line Items]
Common stock conversion right to receive cash per share	$ 28.00
Declared special dividend per share		$ 0.75	$ 0.75	$ 0.75	$ 0.75
Receipt of consents from Epoch clients representing minimum percentage of Epoch's management fee revenues	80.00%
Fees payable to TD in case of agreement termination	$ 20
Legal and investment banking fees						$ 2.8
Stockholders holding percentage of voting power in Epoch's	28.00%