Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Jun. 30, 2014
Goodwill [Line Items]
Goodwill	$ 1,451,728		$ 1,476,207
Accumulated impairment losses	(120,811)		(120,811)
Subtotal	1,330,917		1,355,396
Goodwill acquired	26,761
Foreign translation adjustment	(606)
Other	(1,676)	[1]
Animal Hospital [Member]
Goodwill [Line Items]
Goodwill	1,216,581		1,241,063
Accumulated impairment losses	0		0
Subtotal	1,216,581		1,241,063
Goodwill acquired	26,761
Foreign translation adjustment	(603)
Other	(1,676)	[1]
Laboratory [Member]
Goodwill [Line Items]
Goodwill	96,871		96,868
Accumulated impairment losses	0		0
Subtotal	96,871		96,868
Goodwill acquired	0
Foreign translation adjustment	(3)
Other	0	[1]
All Other Segments [Member]
Goodwill [Line Items]
Goodwill	138,276		138,276
Accumulated impairment losses	(120,811)		(120,811)
Subtotal	17,465		17,465
Goodwill acquired	0
Foreign translation adjustment	0
Other	$ 0	[1]

[1] "Other" primarily includes immaterial measurement period adjustments and an immaterial write-off related to the sale of an animal hospital.