Summarize Activity of the Net Product Revenue Allowance and Reserve Categories (Detail) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 27,198	$ 15,796
Provision related to current period sales	124,571	71,318
Provision related to prior period sales	(1,220)	(489)
Credits/payments made for current period sales	(82,300)	(40,110)
Credits/payments made for prior period sales	(21,623)	(14,203)
Ending balance	46,626	32,312
Trade Allowances
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	3,743	4,296
Provision related to current period sales	24,780	15,823
Provision related to prior period sales	(297)	(87)
Credits/payments made for current period sales	(11,061)	(11,086)
Credits/payments made for prior period sales	(3,107)	(4,180)
Ending balance	14,058	4,766
Rebates, Chargebacks and Discounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	20,915	9,881
Provision related to current period sales	87,499	46,553
Provision related to prior period sales	(841)	(402)
Credits/payments made for current period sales	(62,014)	(22,236)
Credits/payments made for prior period sales	(16,722)	(8,492)
Ending balance	28,837	25,304
Product Returns
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	859	535
Provision related to current period sales	1,496	403
Credits/payments made for current period sales	(391)
Credits/payments made for prior period sales	(24)	(247)
Ending balance	1,940	691
Other Incentives
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	1,681	1,084
Provision related to current period sales	10,796	8,539
Provision related to prior period sales	(82)
Credits/payments made for current period sales	(8,834)	(6,788)
Credits/payments made for prior period sales	(1,770)	(1,284)
Ending balance	$ 1,791	$ 1,551

Credits/payments made for prior period sales.

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- Definition

Provision related to prior period sales.

+ References

No definition available.

+ Details

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- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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- Definition

Amount of increase in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from charges to costs and expenses.

+ References

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Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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