Equity Investments (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended		3 Months Ended	6 Months Ended		1 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2013 BioClinica, Inc.	Dec. 31, 2012 BioClinica, Inc.	Jun. 30, 2012 Noveprim Limited	Jun. 30, 2012 Noveprim Limited	Jan. 31, 2013 Noveprim Limited	Jun. 30, 2013 Caprion Proteomics	Jul. 31, 2012 Caprion Proteomics
Disclosures on investments
Proceeds from sale of investment			$ 17,781,000	$ 0	$ 17,100,000						$ 4,700,000
Cost basis of investment					1,400,000
Gain on sale of investment					15,700,000
Carrying value						13,500,000
Increase in carrying value of investment during period, before tax					3,600,000
Increase in carrying value of investment during period, net of tax					2,800,000
Unrealized gain on an investment balance, before tax						12,100,000
Unrealized gain on an investment balance, net of tax						7,400,000
Equity position terminated (as a percent)									47.00%
Carrying value							0	0
Other-than-temporary impairment of equity investment	0	7,373,000	0	7,373,000			7,400,000
Income (loss) recognized	0	(81,000)	0	17,000			(100,000)	17,000
Cost method investments ownership sold (as a percent)											100.00%
Gain on sale of investment										$ 700,000	$ 1,500,000