Acquisitions and Dispositions - Summary of Purchase Price (Parenthetical) (Detail)	Jun. 30, 2017 $ / shares shares
Business Combinations [Abstract]
Business acquisition share price \| $ / shares	$ 23.00
Business acquisition number of shares acquired \| shares	39,359,000

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

No definition available.

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