Summary of Significant Accounting Policies - Calculation of Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Calculation of Basic and Diluted Earnings per Share
Net income attributable to VCA Inc.	$ 63,595	$ 54,854	$ 54,299	$ 38,301	$ 28,359	$ 27,452	$ 45,584	$ 34,043	$ 211,049	$ 135,438	$ 137,511
Weighted average common shares outstanding:
Basic (shares)									81,443	86,656	88,621
Effect of dilutive potential common stock:
Stock options (shares)									330	302	305
Nonvested shares and units (shares)									641	867	737
Diluted (shares)									82,414	87,825	89,663
Basic earnings per common share (USD per share)	$ 0.79	$ 0.68	$ 0.66	$ 0.47	$ 0.34	$ 0.32	$ 0.52	$ 0.39	$ 2.59	$ 1.56	$ 1.55
Diluted earnings per common share (USD per share)	$ 0.78	$ 0.67	$ 0.65	$ 0.46	$ 0.33	$ 0.31	$ 0.51	$ 0.38	$ 2.56	$ 1.54	$ 1.53