Nature of Operations and Basis of Presentation - Additional Information (Detail)	Mar. 31, 2018
ESSA Advisory Services, LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage ownership of wholly owned subsidiary	100.00%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant