Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components Of Income Tax Expense Benefit [Line Items]
U.S. Federal	$ 85,585	$ 74,561	$ 62,616
State	9,431	10,325	9,234
Foreign	9,661	6,953	5,810
Income tax expense	104,677	91,839	77,660
Current	99,990	91,550	69,071
Deferred	4,687	289	8,589
Income tax expense	$ 104,677	$ 91,839	$ 77,660

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Section S99
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-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Current Tax Expense (or Benefit)
-URI http://asc.fasb.org/extlink&oid=6509736

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 6
-Section I
-Subsection 7

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Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Deferred Tax Expense (or Benefit)
-URI http://asc.fasb.org/extlink&oid=6510177

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-Publisher FASB
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Amount of current and deferred federal income tax expense (benefit) attributable to income (loss) from continuing operations.

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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of current and deferred foreign income tax expense (benefit) attributable to income (loss) from continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of state and local current and deferred income tax expense (benefit) attributable to continuing operations.

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Components Of Income Tax Expense Benefit [Line Items]

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