Employee Benefits and Incentive Plans - Summary of Information on Options Granted under Executive Incentive Plan (Detail)	12 Months Ended
Dec. 31, 2016 $ / shares shares
0.00-25.36 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price, Lower Limit	$ 0.00
Exercise Price, Upper Limit	$ 25.36
Outstanding Number of Options \| shares	389,018
Outstanding Average Remaining Contractual Life (years)	6 years 8 months 12 days
Outstanding Weighted Average Exercise Price	$ 23.67
Exercisable Number of Options \| shares	244,723
Exercisable Weighted Average Exercise Price	$ 23.47
25.37-33.51 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price, Lower Limit	25.37
Exercise Price, Upper Limit	$ 28.80
Outstanding Number of Options \| shares	1,267,788
Outstanding Average Remaining Contractual Life (years)	4 years 9 months 11 days
Outstanding Weighted Average Exercise Price	$ 25.52
Exercisable Number of Options \| shares	1,267,788
Exercisable Weighted Average Exercise Price	$ 25.52
33.52-50.87 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price, Lower Limit	28.81
Exercise Price, Upper Limit	$ 33.52
Outstanding Number of Options \| shares	490,126
Outstanding Average Remaining Contractual Life (years)	4 years 2 months 16 days
Outstanding Weighted Average Exercise Price	$ 33.45
Exercisable Number of Options \| shares	490,126
Exercisable Weighted Average Exercise Price	$ 33.45
50.888-84.80 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price, Lower Limit	33.53
Exercise Price, Upper Limit	$ 84.80
Outstanding Number of Options \| shares	22,373
Outstanding Average Remaining Contractual Life (years)	2 years 7 months 17 days
Outstanding Weighted Average Exercise Price	$ 71.54
Exercisable Number of Options \| shares	22,373
Exercisable Weighted Average Exercise Price	$ 71.54
0.00-84.80 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Exercise Price, Lower Limit	0.00
Exercise Price, Upper Limit	$ 84.80
Outstanding Number of Options \| shares	2,169,305
Outstanding Average Remaining Contractual Life (years)	4 years 11 months 19 days
Outstanding Weighted Average Exercise Price	$ 27.45
Exercisable Number of Options \| shares	2,025,010
Exercisable Weighted Average Exercise Price	$ 27.70

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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