Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
Dec. 31, 2012
Equipment and furniture
Significant Accounting Policies [Line Items]
Estimated useful life	60 years
Computer software and hardware
Significant Accounting Policies [Line Items]
Estimated useful life	36 months
Leasehold Improvements
Significant Accounting Policies [Line Items]
Estimated useful life description	Leasehold improvements are amortized over the life of the lease or the life of the improvement, whichever is shorter.

Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-URI http://asc.fasb.org/subtopic&trid=2155824

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration