Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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- Definition

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+ References

No definition available.

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 28A
-URI http://asc.fasb.org/extlink&oid=109260490&loc=d3e1500-109256

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-Name Accounting Standards Codification
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-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Net Income (Loss) Per Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average antidilutive securities excluded from computation of earnings per share (in shares)		3.2		3.1
Weighted average potentially dilutive securities included in calculation of diluted securities (in shares)		10.9		12.1
Stock Options and Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average antidilutive securities excluded from computation of earnings per share (in shares)	18.0		18.4