Schedule of Acquisition of Intangible Assets (Detail) (Westerman, Inc, USD $) In Thousands, unless otherwise specified	1 Months Ended
	Sep. 17, 2012
Business Acquisition [Line Items]
Acquired finite lived intangible assets	$ 18,318
Customer Relationships
Business Acquisition [Line Items]
Acquired finite lived intangible assets	12,796
Useful Life (Years)	10 years
Trade Names
Business Acquisition [Line Items]
Acquired finite lived intangible assets	2,986
Trade Names | Minimum
Business Acquisition [Line Items]
Useful Life (Years)	3 years
Trade Names | Maximum
Business Acquisition [Line Items]
Useful Life (Years)	4 years
Non-compete Agreements
Business Acquisition [Line Items]
Acquired finite lived intangible assets	1,050
Useful Life (Years)	5 years
Other Intangible Assets
Business Acquisition [Line Items]
Acquired finite lived intangible assets	$ 1,486
Other Intangible Assets | Minimum
Business Acquisition [Line Items]
Useful Life (Years)	1 year
Other Intangible Assets | Maximum
Business Acquisition [Line Items]
Useful Life (Years)	3 years