Assumptions Used to Determine Benefit Obligation (Detail)	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Defined Contribution Plans Disclosures [Line Items]
Discount rate	1.25%	2.25%
Rate of compensation	1.50%	1.50%

Expected rate of compensation increases (for pay-related plans).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (k)(2)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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