Concentration of Credit Risk - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Risks And Uncertainties [Abstract]
Cash in bank deposit accounts in excess of the FDIC insured amount	$ 250us-gaap_CashFDICInsuredAmount

The amount of cash deposited in financial institutions as of the balance sheet date that is insured by the Federal Deposit Insurance Corporation.

No definition available.

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