Components of Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2013	Dec. 31, 2012
Schedule Of Goodwill And Intangible Assets [Line Items]
Gross Carrying Amount	$ 49,251	$ 49,251
Accumulated Amortization	12,662	10,968
Customer Relationships
Schedule Of Goodwill And Intangible Assets [Line Items]
Weighted Average Life	16 years 4 months 24 days
Gross Carrying Amount	48,261	48,261
Accumulated Amortization	12,219	10,663
Other Intangible Assets
Schedule Of Goodwill And Intangible Assets [Line Items]
Weighted Average Life	2 years 6 months
Gross Carrying Amount	990	990
Accumulated Amortization	$ 443	$ 305

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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