Commitments and Contingencies - Narrative (Details) $ in Thousands			3 Months Ended	12 Months Ended
	Jul. 16, 2014 plaintiff	May 07, 2014 claim	Sep. 30, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Commitments and Contingencies (Textual) [Abstract]
Minimum period of lease including renewal options				5 years
Maximum period of lease including renewal options				35 years
Total rent expense				$ 92,000	$ 76,700	$ 69,700
Total rental income				1,200	1,100	1,200
Purchase commitments of products and services through 2019				16,900
Potential earnout payment				11,200
Earn-outs				9,200	3,500
Total outstanding holdbacks				11,600	6,500
Amount paid to sellers for unused portion of holdbacks				9,000	3,200	700
Gain on insurance proceeds			$ 4,500	$ 0	4,523	0
California Wildfire
Commitments and Contingencies (Textual) [Abstract]
Loss recorded in connection with unusual event						18,900
Insurance proceeds received						20,000
Gain from unusual event						1,100
Insurance receivable						$ 8,000
Gain on insurance proceeds					$ 4,500
Jorge Duran vs. VCA Animal Hospitals
Commitments and Contingencies (Textual) [Abstract]
Number of claims dismissed | claim		4
Total number of claims | claim		8
Kimba Bradsbery and Cheri Brakensiek vs. Vicar Operating, Inc.
Commitments and Contingencies (Textual) [Abstract]
Number of plaintiffs | plaintiff	2