Business Segment Information (Tables)

6 Months Ended

Jun. 28, 2014

Segment Reporting [Abstract]

Schedule of Sales and Other Financial Information by Business Segment

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

	Three Months Ended				Six Months Ended
	June 28, 2014		June 29, 2013		June 28, 2014		June 29, 2013
Research Models and Services
Revenue	$	133,120	$	129,759	$	265,615	$	264,632
Gross margin	52,450		49,020		104,097		104,476
Operating income	34,234		33,296		69,678		73,773
Depreciation and amortization	7,165		7,192		14,364		14,094
Capital expenditures	2,478		3,991		7,711		6,209
Discovery and Safety Assessment
Revenue	$	142,614	$	107,490	$	247,752	$	209,281
Gross margin	39,457		25,534		65,116		48,051
Operating income	17,798		11,261		29,511		19,704
Depreciation and amortization	13,241		9,369		22,012		18,783
Capital expenditures	4,340		3,064		8,051		4,856
Manufacturing Support
Revenue	65,445		55,684		127,180		110,258
Gross margin	33,727		28,016		65,234		54,254
Operating income	20,455		16,008		38,871		30,451
Depreciation and amortization	3,894		3,849		7,975		7,543
Capital expenditures	2,497		2,740		4,743		5,158

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						Six Months Ended
	June 28, 2014			June 29, 2013			June 28, 2014			June 29, 2013
Total segment operating income	$	72,487		$	60,565		$	138,060		$	123,928
Unallocated corporate overhead	(21,462		)	(17,377		)	(47,329		)	(37,977		)
Consolidated operating income	$	51,025		$	43,188		$	90,731		$	85,951

Schedule of Net Sales for Each Significant Service Area

for each significant product or service area is as follows:

	Three Months Ended				Six Months Ended
	June 28, 2014		June 29, 2013		June 28, 2014		June 29, 2013
Research models	$	87,814	$	85,959	$	174,796	$	176,216
Research model services	45,306		43,800		90,819		88,416
Total research models and services	133,120		129,759		265,615		264,632
Total discovery and safety assessment	142,614		107,490		247,752		209,281
Endotoxin and Microbial Detection	33,579		27,671		66,045		54,883
Other manufacturing support	31,866		28,013		61,135		55,375
Total manufacturing support	$	65,445	$	55,684	$	127,180	$	110,258
Total revenue	$	341,179	$	292,933	$	640,547	$	584,171

Summary of Unallocated Corporate Overhead

A summary of unallocated corporate overhead consists of the following:

	Three Months Ended						Six Months Ended
	June 28, 2014			June 29, 2013			June 28, 2014		June 29, 2013
Stock-based compensation expense	$	4,905		$	3,470		$	8,607	$	6,667
U.S. retirement plans	809			1,042			1,453		2,342
Audit, tax and related expense	1,226			1,089			3,131		2,324
Salary and bonus	6,919			5,471			13,058		10,226
Global IT	3,152			2,860			6,021		5,446
Employee health, long-term disability and fringe benefit expense	(1,685		)	(1,656		)	634		572
Consulting and professional services	893			1,315			2,075		2,003
Depreciation expense	1,599			1,572			3,199		3,142
Costs associated with evaluation and integration of acquisitions	1,371			194			4,676		680
Other general unallocated corporate expenses	2,273			2,020			4,475		4,575
Total unallocated corporate overhead costs	$	21,462		$	17,377		$	47,329	$	37,977