Basis of Presentation - Additional Information (Detail)	1 Months Ended
Dec. 31, 2014 Segments Segment	Nov. 30, 2013
Basis Of Presentation [Line Items]
Number of reporting segments	4
NHUMO [Member]
Basis Of Presentation [Line Items]
Percentage acquisition		60.00%
Ownership percentage prior to acquisition		40.00%

Percentage of voting equity interests acquired at the acquisition date in the business combination.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

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