Accounts Receivable - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Government receivables unbilled amount	$ 2.5	$ 2.4
U.S. Government Audit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Government receivables unbilled amount	$ 2.4

Unbilled amounts (net of unliquidated progress payments) of government contract receivables.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 912

-SubTopic 310

-Section 45

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=6471842&loc=d3e55376-109406

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