Business Segment Information (Tables)

3 Months Ended

Sep. 28, 2013

Segment Reporting [Abstract]

Schedule of Sales and Other Financial Information by Business Segment

The following table presents sales and other financial information by business segment.

	Three Months Ended				Nine Months Ended
	September 28, 2013		September 29, 2012		September 28, 2013		September 29, 2012
Research Models and Services
Net sales	$	173,405	$	166,484	$	534,867	$	523,247
Gross margin	65,710		65,902		221,916		224,364
Operating income	40,260		43,389		145,193		158,398
Depreciation and amortization	16,876		9,670		37,378		27,697
Capital expenditures	6,110		7,423		16,464		27,892
Preclinical Services
Net sales	$	118,724	$	112,202	$	341,433	$	326,143
Gross margin	34,216		27,358		84,791		76,693
Operating income	18,636		10,975		37,631		25,958
Depreciation and amortization	10,039		10,880		29,957		32,920
Capital expenditures	2,986		2,819		8,855		5,903

Reconciliation of Segment Operating Income to Consolidated Operating Income

A reconciliation of segment operating income to consolidated operating income is as follows:

	Three Months Ended						Nine Months Ended
	September 28, 2013			September 29, 2012			September 28, 2013			September 29, 2012
Total segment operating income	$	58,896		$	54,364		$	182,824		$	184,356
Unallocated corporate overhead	(18,053		)	(16,682		)	(56,030		)	(53,660		)
Consolidated operating income	$	40,843		$	37,682		$	126,794		$	130,696

Schedule of Net Sales for Each Significant Service Area

Net sales for each significant service area are as follows:

	Three Months Ended				Nine Months Ended
	September 28, 2013		September 29, 2012		September 28, 2013		September 29, 2012
Research models	$	92,969	$	90,877	$	294,993	$	293,575
Research model services	52,105		53,400		156,661		163,247
EMD	28,331		22,207		83,213		66,425
Total research models and services	173,405		166,484		534,867		523,247
Total preclinical services	118,724		112,202		341,433		326,143
Total sales	$	292,129	$	278,686	$	876,300	$	849,390

Summary of Unallocated Corporate Overhead

A summary of unallocated corporate overhead consists of the following:

	Three Months Ended						Nine Months Ended
	September 28, 2013			September 29, 2012			September 28, 2013			September 29, 2012
Stock-based compensation expense	$	3,260		$	2,827		$	9,927		$	8,512
U.S. retirement plans	1,275			1,276			3,617			3,662
Audit, tax and related expense	811			842			3,135			2,133
Salary and bonus	5,831			4,813			16,057			14,602
Global IT	3,002			3,285			8,448			9,501
Employee health, long-term disability and fringe benefit expense	(1,470		)	(2,248		)	(898		)	(1,395		)
Consulting and professional services	1,439			1,061			3,443			3,581
Depreciation expense	1,570			1,554			4,712			4,693
Other general unallocated corporate expenses	2,335			3,272			7,589			8,371
Total unallocated corporate overhead costs	$	18,053		$	16,682		$	56,030		$	53,660