Information About Non-Qualified Stock Options Outstanding (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable at Year-End	7,599	8,049
Exercisable Weighted Average Exercise Price at Year-End	$ 31.79	$ 30.06
Nonqualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Outstanding at Year-End	9,906	10,148
Outstanding Weighted Average Remaining Contractual Life (in years)	5 years 8 months 12 days
Outstanding Weighted Price Average Exercise at Year-End	$ 33.18	$ 31.23
Number Exercisable at Year-End	7,599
Exercisable Weighted Average Exercise Price at Year-End	$ 31.79
Nonqualified Stock Options \| Range 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental Changes in Stock Price Lower Range Limit	$ 10.01
Incremental Changes in Stock Price Upper Range Limit	$ 20.00
Number Outstanding at Year-End	6
Outstanding Weighted Average Remaining Contractual Life (in years)	4 months 24 days
Outstanding Weighted Price Average Exercise at Year-End	$ 18.02
Number Exercisable at Year-End	6
Exercisable Weighted Average Exercise Price at Year-End	$ 18.02
Nonqualified Stock Options \| Range 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental Changes in Stock Price Lower Range Limit	$ 20.01
Incremental Changes in Stock Price Upper Range Limit	$ 30.00
Number Outstanding at Year-End	3,525
Outstanding Weighted Average Remaining Contractual Life (in years)	3 years 8 months 12 days
Outstanding Weighted Price Average Exercise at Year-End	$ 26.45
Number Exercisable at Year-End	3,522
Exercisable Weighted Average Exercise Price at Year-End	$ 26.45
Nonqualified Stock Options \| Range 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental Changes in Stock Price Lower Range Limit	$ 30.01
Incremental Changes in Stock Price Upper Range Limit	$ 40.00
Number Outstanding at Year-End	5,366
Outstanding Weighted Average Remaining Contractual Life (in years)	7 years 2 months 12 days
Outstanding Weighted Price Average Exercise at Year-End	$ 35.40
Number Exercisable at Year-End	3,065
Exercisable Weighted Average Exercise Price at Year-End	$ 35.40
Nonqualified Stock Options \| Range 4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental Changes in Stock Price Lower Range Limit	$ 40.01
Incremental Changes in Stock Price Upper Range Limit	$ 50.00
Number Outstanding at Year-End	1,009
Outstanding Weighted Average Remaining Contractual Life (in years)	4 years 10 months 24 days
Outstanding Weighted Price Average Exercise at Year-End	$ 44.99
Number Exercisable at Year-End	1,006
Exercisable Weighted Average Exercise Price at Year-End	$ 44.90

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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.

+ 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)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

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.

+ 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)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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-Section 50

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-Subparagraph (c)(1)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

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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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

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 Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

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

+ References

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- Definition

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

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