Compensation Agreements and Plans - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation And Retirement Disclosure [Line Items]
Gain (loss) in fair value of restricted stock issued	$ 5,000,000	$ 2,500,000	$ (4,800,000)
BioMarin Retirement Savings Plan
Compensation And Retirement Disclosure [Line Items]
Employee contribution of their current compensation	100.00%
Company's contribution to match employees contribution	100.00%
Employer contribution of maximum percentage over employee's annual compensation	6.00%
Employer contribution over employee's annual compensation	$ 12,000
Employer contribution over employee's annual compensation starting next fiscal year	$ 14,000
Company's savings plan contribution vesting period, years	4 years
Company's contribution from employment commencement	$ 16,000,000	15,100,000	$ 8,300,000
Deferred Compensation Plan
Compensation And Retirement Disclosure [Line Items]
Fair value of company stock held	$ 19,400,000	$ 25,500,000

Compensation and retirement disclosure.

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- Definition

Employee contribution of their current compensation

+ References

No definition available.

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- Definition

Gain (loss) in the fair value of company common stock held in the deferred compensation plan.

+ References

No definition available.

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- Definition

Value of common stock issued to a trust (for example, but not limited to, rabbi trust) set up specifically to accumulate stock for the sole purpose of distribution to participating employees.

+ References

No definition available.

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- Definition

Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6409961&loc=d3e20487-108367

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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Percentage employer matches of the employee's percentage contribution matched.

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- Definition

Maximum amount the employee may contribute to a defined contribution plan.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

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