Acquisitions Acquisition (Details)	3 Months Ended		9 Months Ended			9 Months Ended		12 Months Ended		9 Months Ended				12 Months Ended			12 Months Ended	9 Months Ended				12 Months Ended
	Sep. 30, 2013 USD ($) Provinces	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($) Provinces	Sep. 30, 2012 USD ($)	Mar. 31, 2012 Provinces	Sep. 30, 2013 AVC Acquisition [Member] USD ($) Hospital	Sep. 30, 2012 AVC Acquisition [Member] Hospital	Dec. 31, 2012 AVC Acquisition [Member] USD ($) Hospital	Dec. 31, 2012 AVC Acquisition [Member] CAD	Sep. 30, 2013 Animal Hospital [Member] Hospital	Sep. 30, 2012 Animal Hospital [Member] Hospital	Sep. 30, 2013 Animal Hospitals And Laboratory Acquisitions [Member] USD ($)	Sep. 30, 2012 Animal Hospitals And Laboratory Acquisitions [Member] USD ($)	Dec. 31, 2012 AVC [Member] USD ($)	Dec. 31, 2012 ThinkPetsAcquisition [Member] USD ($)	Sep. 30, 2013 ThinkPetsAcquisition [Member] USD ($)	Dec. 31, 2012 Think Pets Inc [Member]	Sep. 30, 2013 Laboratories Acquisitions [Member] Laboratory	Sep. 30, 2012 Laboratories Acquisitions [Member] Laboratory	Sep. 30, 2013 Laboratory [Member] Hospital	Sep. 30, 2012 Laboratory [Member] Laboratory	Dec. 31, 2012 Customer Relationships [Member] AVC [Member]	Dec. 31, 2012 Customer Relationships [Member] Think Pets Inc [Member]	Dec. 31, 2012 Technology And Trademarks [Member] Think Pets Inc [Member]	Dec. 31, 2012 Trademarks [Member] AVC [Member]	Dec. 31, 2012 Trademarks [Member] Think Pets Inc [Member]	Dec. 31, 2012 Noncompete Agreements [Member] AVC [Member]
Business Acquisition Summary Of Acquired Properties [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life														6 years			8 years					5 years	9 years	4 years	10 years	2 years	3 years
Number of Businesses Acquired						0	44	44	44	14	24							1	0
Number Of Canadian Provinces	4		4		3
Number Of Laboratories Created																		0	2
Change In Number Of Laboratories Owned During The Period																				1	2
Annualized Revenue At Acquisition CAD									95,000,000
Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount						362,000						12,900,000	40,000,000			821,000
Payments To Acquire Real Estate For Use By Owner	1,200,000		1,208,000	1,602,000
Preliminary Purchase Price CAD									81,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid	39,640,000	108,031,000	39,640,000	108,031,000				48,819,000				39,640,000	51,744,000		7,468,000
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned															10,500,000
Business Acquisition Cost Of Acquired Entity Cash Paid For Hold Backs												892,000	1,475,000		1,050,000
Business Acquisition, Contingent Consideration, at Fair Value	(1,120,000)	(934,000)	(1,120,000)	(934,000)								1,120,000	934,000
Business Combination, Consideration Transferred								74,734,000				44,012,000	54,153,000		19,018,000
Business Acquisition, Purchase Price Allocation, Tangible Assets								11,694,000				13,494,000	1,995,000		2,093,000
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets								25,170,000				12,774,000	9,184,000		7,221,000
Business Acquisition, Purchase Price Allocation, Goodwill Amount								79,707,000				32,557,000	42,974,000		12,155,000
Business Acquisition, Purchase Price Allocation, Liabilities Assumed								(21,826,000)				(9,407,000)	0		(2,451,000)
business acquisition purchase price allocation total								94,745,000				49,418,000	54,153,000
Noncontrolling Interest, Increase from Business Combination		(8,161,000)	5,406,000	(8,161,000)				(8,161,000)				(5,406,000)	0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value	0	(11,850,000)	0	(11,850,000)				(11,850,000)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net								74,734,000				44,012,000	54,153,000		19,018,000
Business Acquisitions Cash Paid To Debtholders								25,915,000				2,360,000	0
Business Acquisition, Percentage of Voting Interests Acquired															100.00%
Business Acquisition Cost Of Acquired Entity Preliminary Purchase Price														81,000,000	21,000,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares															473,389
business acquisition cash including acquired cash															10,500,000
Number Of Acquired Hospitals Relocated To Existing Hospitals										(2)	(4)
Number Of Properties Sold Closed Or Merged										(15)	(4)
Change In Number Of Animal Hospitals Owned During The Period										(3)	60
US Annualized Revenue At Acquisition								$ 95,000,000