Commitments and Contingencies - Estimated Future Cash Outlays Related to Principal Contractual Obligations (Detail) $ in Millions	Dec. 31, 2017 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2018	$ 62.9
2019	2.5
2020	2.4
Thereafter	0.0
Total	67.8
Obligations includes agreement to pay in lieu of certain future royalty paymentsAmount	$ 45.0

No definition available.

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- Definition

Amount of the recorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=73718637&loc=d3e25383-109308

+ Details

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Period Type:	instant

- Definition

Amount of the recorded unconditional purchase obligation maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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- Definition

Amount of the recorded unconditional purchase obligation maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Amount of the recorded unconditional purchase obligation maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Amount of the recorded unconditional purchase obligation maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

The amount the entity has committed to make for future royalty guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 440
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473578&loc=d3e63223-108013

+ Details

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