Calculation of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Calculation of Basic and Diluted Earnings per Share
Net income attributable to VCA Inc.	$ 64,050	$ 54,299	$ 110,277	$ 92,600
Weighted-average common shares outstanding:
Basic (in shares)	80,835,000	81,956,000	80,806,000	82,150,000
Effect of dilutive potential common shares:
Stock options (in shares)	295,000	334,000	294,000	337,000
Non-vested shares and units (in shares)	599,000	794,000	530,000	740,000
Diluted (in shares)	81,729,000	83,084,000	81,630,000	83,227,000
Basic earnings per share (in dollars per share)	$ 0.79	$ 0.66	$ 1.36	$ 1.13
Diluted earnings per share (in dollars per share)	$ 0.78	$ 0.65	$ 1.35	$ 1.11
Calculation of Earnings per Share (Textuals) [Abstract]
Potential common shares excluded from the computation of diluted earnings per share (in shares)	21,122,000	0	24,047,000	38,120,000