Intangibles, Net (Tables)

12 Months Ended

Jul. 31, 2011

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible assets for 31 July 2011 and 31 July 2010

	July 31, 2011
	Gross Carrying Amount		Accumulated Amortization			Net Book Value		Weighted Average Remaining Useful Life (in years)
Amortized intangible assets:
Covenants not to compete	$	10,896	$	(10,486	)	$	410		3
Supply contracts		27,238		(15,409	)		11,829		3
Licenses and databases		1,337		(828	)		509		3
	$	39,471	$	(26,723	)	$	12,748

 

	July 31 , 2010
	Gross Carrying Amount		Accumulated Amortization			Net Book Value		Weighted Average Remaining Useful Life (in years)
Amortized intangible assets:
Covenants not to compete	$	10,697	$	(10,233	)	$	464		1
Supply contracts		22,365		(10,521	)		11,844		4
Licenses and databases		1,317		(609	)		708		4
	$	34,379	$	(21,363	)	$	13,016

Aggregate amortization expense on intangible assets

2012	$	4,926
2013		4,124
2014		1,338
2015		1,090
2016		875
Thereafter		395
	$	12,748