Organization And Presentation - Additional information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Organization And Business Activities [Line Items]
Minority interest ownership percentage	50.00%
Income From Continuing Operations
Organization And Business Activities [Line Items]
Income tax expense (benefit)	$ (1.6)
Other Comprehensive Income
Organization And Business Activities [Line Items]
Income tax expense (benefit)	$ 1.6
Minimum
Organization And Business Activities [Line Items]
Equity method investment ownership percentage	20.00%
Maximum
Organization And Business Activities [Line Items]
Equity method investment ownership percentage	50.00%

The change during the period in the entity's deferred tax assets and liabilities attributable to continuing operations as determined by applying enacted tax laws other than federal, domestic, foreign, state or local. Items affecting deferred income taxes and required to be disclosed, but not included elsewhere, would also be designated as "Other"; for example, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity and adjustments to be beginning-of-year balance of a valuation allowance because of a change in circumstance that causes a change in judgment about the realizability of the related deferred tax asset in future periods.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (g),(h)

-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

-SubTopic 10

-Section S99

-Paragraph 1

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

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 6.I.7)

-URI http://asc.fasb.org/extlink&oid=6889476&loc=d3e330036-122817

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 45

-Subparagraph g, h

-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 6: 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

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section I

-Subsection 7

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 8, 16, 17, 289

-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.

+ Details

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References+ Details