Contingencies - Additional Information (Detail) - Vainer Private Civil Suit $ in Thousands	6 Months Ended
Jun. 30, 2015 USD ($)
Other Commitments [Line Items]
Litigation settlement amount	$ 450,000
Legal fees	$ 45,000

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=26872669&loc=d3e20235-122688

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