Commitments and Contingencies - Additional Information (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Indemnification Obligation [Member]
Loss Contingencies [Line Items]
Indemnification obligations, liabilities	$ 0	$ 0

Amount of loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant