Summary of Significant Accounting Policies (Details 7) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Calculation of Basic and Diluted Earnings per Share
Net income attributable to VCA Antech, Inc.	$ (3,215)	$ 30,169	$ 39,612	$ 28,839	$ 21,473	$ 27,431	$ 29,404	$ 31,935	$ 95,405	$ 110,243	$ 131,428
Weighted-average common shares outstanding:
Basic									86,606	86,049	85,077
Effect of dilutive potential common stock:
Stock options									560	753	785
Nonvested shares									228	249	235
Diluted									87,394	87,051	86,097
Basic earnings per common share	$ (0.04)	$ 0.35	$ 0.46	$ 0.33	$ 0.25	$ 0.32	$ 0.34	$ 0.37	$ 1.10	$ 1.28	$ 1.54
Diluted earnings per common share	$ (0.04)	$ 0.35	$ 0.45	$ 0.33	$ 0.25	$ 0.32	$ 0.34	$ 0.37	$ 1.09	$ 1.27	$ 1.53