Stockholders' Equity (Series B Junior Participating Preferred Share Purchase Right) - Additional Information (Detail)	Apr. 18, 2017 $ / shares
Share Repurchase Plan [Member] \| Series B Junior Participating Preferred Stock [Member]
Subsequent Event [Line Items]
Exercise price per one one-hundredth of each preferred share	$ 125.00

Exercise price per share or per unit of warrants or rights outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant