Net Income (Loss) Per Common Share - Calculation of Diluted Net Income (Loss) Per Share (Parenthetical) (Detail)	3 Months Ended	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Earnings Per Share [Abstract]
Dilutive effects from equity instruments	0	0	0

Additional shared included in the calculation of diluted EPS as a result of the potentially dilutive effect of equity forward arrangements using the reverse treasury stock method.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 35

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e2366-109256

Name:	us-gaap_IncrementalCommonSharesAttributableToEquityForwardAgreements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration