Acquisitions - Narrative (Details) (BioReliance Holdings, Inc., USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Jan. 31, 2012
BioReliance Holdings, Inc.
Business Acquisition [Line Items]
Acquisition completion date	Jan. 31, 2012
Acquisition, consideration			$ 353
Cash acquired in acquisition			11
Net sales of acquired company	111
Pro forma net sales	$ 2,632	$ 2,631