XML 30 R87.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Measurement - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Assets fair value disclosure nonrecurring basis $ 0us-gaap_AssetsFairValueDisclosureNonrecurring $ 0us-gaap_AssetsFairValueDisclosureNonrecurring $ 0us-gaap_AssetsFairValueDisclosureNonrecurring
Assets measured at fair value nonrecurring basis, loss incurred $ 0us-gaap_AssetsFairValueAdjustment $ 0us-gaap_AssetsFairValueAdjustment $ 0us-gaap_AssetsFairValueAdjustment