Discontinued Operations - Summary Of Financial Information For Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Discontinued Operations And Disposal Groups [Abstract]
Revenues	$ 493,233	$ 430,065
Income from discontinued operations before taxes	46,576	22,862
Gain on disposal of discontinued operations before taxes	17,962
Provision for income taxes	(47,603)	(8,858)
Income from discontinued operations, net of taxes	$ 16,935	$ 14,004

Amount of gain (loss), before tax expense or benefit and not previously recognized, resulting from the sale of a business component.

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Pretax income (loss) from operations of a business component (exclusive of any gain (loss) on disposal, or provision therefore) during the reporting period, until its disposal.

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Tax effect allocated to a disposal group that is classified as a component of the entity reported as a separate component of income before extraordinary items. Includes the tax effects of the following: income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Amount of sales or other form of revenues attributable to the disposal group, including a component of the entity (discontinued operation), during the reporting period.

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Amount of income (loss) from a disposal group, net of income tax before extraordinary items allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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