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Summary of Significant Accounting Policies (Income Taxes) - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016 USD ($)
Income Tax Examination [Line Items]
Total amount of unrecognized tax benefits relating to uncertain tax positions	$ 59,500,000
Amount of unrecognized tax benefits change from year end relating to uncertain tax positions	5,000,000
Maximum [Member]
Income Tax Examination [Line Items]
Reasonably possible reduction to the balance of unrecognized tax benefits in succeeding 12 months	$ 32,100,000
Tax Year 2010 [Member]
Income Tax Examination [Line Items]
Income tax examination, year completed	2010
Tax Year 2011 [Member]
Income Tax Examination [Line Items]
Income tax examination, year completed	2011
Tax Year 2012 [Member]
Income Tax Examination [Line Items]
Income tax examination, year completed	2012

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (d)(3)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32718-109319

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

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-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

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