Differences between Statutory Federal Income Tax Rate and Effective Income Tax Rate (Detail)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Statutory Federal Tax Rate [Line Items]
Statutory federal income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	1.00%	0.90%	16.40%
Valuation allowance	41.30%	8.80%	7646.40%
Bad debt deduction	(24.90%)
Asset dispositions and write-offs	(29.50%)
Non-deductible acquisition costs			41.60%
Tax reserves	(1.00%)	4.10%	(100.90%)
R&D tax credits		(4.10%)	(54.80%)
Foreign tax rate effects	(7.20%)	(22.50%)	(138.00%)
Other, net	0.40%	(1.10%)	64.30%
Effective income tax rate	15.10%	21.10%	7510.00%

Effective Income Tax Rate Reconciliation Bad Debt

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- Definition

Effective Income Tax Rate Reconciliation Tax Reserves

+ References

No definition available.

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- Definition

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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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-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

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-Section S99

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-Subparagraph (SX 210.4-08.(h)(2))

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The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 47

-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 740

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-Section 50

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-Name Accounting Standards Codification

-Topic 740

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-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 6.I)

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- Definition

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to changes in the valuation allowance for deferred tax assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (SAB TOPIC 6.I)

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to the disposition of assets.

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- Definition

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to nondeductible expenses under enacted tax laws, or differences in the methodologies used to determine expense amounts for financial statements prepared in accordance with generally accepted accounting principles, not otherwise listed in the existing taxonomy.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to all other items not otherwise listed in the existing taxonomy.

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- Definition

The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by the state and local income tax expense or benefit, net of the federal tax benefit (expense) thereon, recorded during the period.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by research tax credits generated or utilized under enacted tax laws during the period.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to foreign income tax settlements during the period.

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