Subsequent Event - Additional Information (Detail) - Subsequent Event - S&T - USD ($)	1 Months Ended
Apr. 30, 2016	Apr. 29, 2016
Subsequent Event [Line Items]
Release of collateral, net of expenses incurred		$ 421,000
IRS
Subsequent Event [Line Items]
Expenses incurred in defending IRS challenge	$ 79,000

The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Name:	us-gaap_LegalFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration