Calculation of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Calculation of Basic and Diluted Earnings per Share
Net income attributable to VCA Inc.	$ 54,854	$ 27,452	$ 147,454	$ 107,079
Weighted-average common shares outstanding:
Basic (in shares)	80,815,000	86,274,000	81,700,000	87,543,000
Effect of dilutive potential common shares:
Stock options (in shares)	338,000	324,000	338,000	285,000
Non-vested shares and units (in shares)	642,000	762,000	706,000	837,000
Diluted (in shares)	81,795,000	87,360,000	82,744,000	88,665,000
Basic earnings per share (in dollars per share)	$ 0.68	$ 0.32	$ 1.80	$ 1.22
Diluted earnings per share (in dollars per share)	$ 0.67	$ 0.31	$ 1.78	$ 1.21
Calculation of Earnings per Share (Textuals) [Abstract]
Potential common shares excluded from the computation of diluted earnings per share	0	0		0