Acquisition - Pro forma Financial Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Business Combinations [Abstract]
Revenues	$ 55,096	$ 125,040	$ 112,273
Income before income taxes	20,867	55,860	43,587
Net income	$ 12,423	$ 34,685	$ 25,886
Basic net income per common share	$ 0.34	$ 0.94	$ 0.71
Diluted net income per common share	$ 0.33	$ 0.92	$ 0.68

Business acquisitions pro forma income loss before tax.

No definition available.

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- Definition

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.

+ References

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=25497992&loc=d3e1392-128463

+ Details

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- Definition

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.

+ References

+ Details

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- Definition

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.

+ References

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- Definition

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

+ References

+ Details

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