Business Acquisitions - Schedule of Pro Forma Information Combines Consolidated Results of Company and Business Acquisitions (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014
Business Combinations [Abstract]
Net revenue	$ 1,405,488	$ 1,392,726
Net income	$ 157,668	$ 158,828
Net income per common share, Basic	$ 1.69	$ 1.61
Net income per common share, Diluted	$ 1.67	$ 1.58
Weighted average common shares, Basic	93,361	98,689
Weighted average common shares, Diluted	94,405	100,226

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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The weighted average number of shares or units and dilutive common stock or unit equivalents outstanding in the calculation of proforma diluted earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

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The weighted average number of shares (units) outstanding in the calculation of pro forma basic earnings per share (earnings per unit), which is commonly presented in initial public offerings based on the terms of the offering.

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