Discontinued Operations - Schedule of Operating Results from Discontinued Operations (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Discontinued Operations and Disposal Groups [Abstract]
Gain on sale of discontinued operations, tax	$ 13,973

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

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