The Company (Details)	Dec. 31, 2011 Laboratories Segment	Dec. 31, 2011 ReportingUnits Hospitals States
The Company (Textual) [Abstract]
Number of hospitals operated	541	541
Number of states in which hospitals are operated	41	41
Number of Canadian provinces in which animal hospitals are operated	1	1
Number of states in which the company operate a full-service veterinary diagnostic laboratory network	50	50
Number of laboratories operated	53	53
Number of reporting units	4	4