Acquisitions - Summary of Acquired Intangible Assets Excluding Goodwill (Detail) - Animal Health International [Member] - USD ($)
$ in Thousands |
Jun. 16, 2015 |
Aug. 01, 2015 |
| Business Acquisition [Line Items] |
|
|
| Total amortized intangible assets |
$ 422,000
|
|
| Total identifiable intangible assets |
$ 434,300
|
$ 434,300
|
| Finite lived intangible assets, Weighted average life (years) |
13 years 7 months 6 days
|
|
| Unamortized Trade Names [Member] |
|
|
| Business Acquisition [Line Items] |
|
|
| Unamortized - indefinite lived |
$ 12,300
|
|
| Indefinite lived intangible assets, Weighted average life (years) |
indefinite
|
|
| Customer Relationships [Member] |
|
|
| Business Acquisition [Line Items] |
|
|
| Total amortized intangible assets |
$ 291,900
|
|
| Finite lived intangible assets, Weighted average life (years) |
15 years
|
|
| Amortized Trade Names [Member] |
|
|
| Business Acquisition [Line Items] |
|
|
| Total amortized intangible assets |
$ 111,400
|
|
| Finite lived intangible assets, Weighted average life (years) |
10 years
|
|
| Developed Technology and Other [Member] |
|
|
| Business Acquisition [Line Items] |
|
|
| Total amortized intangible assets |
$ 18,700
|
|
| Finite lived intangible assets, Weighted average life (years) |
12 years 2 months 12 days
|
|