Represents the cumulative amount of the end of term charge which has been accreted as of the balance sheet date.

No definition available.

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Period Type:	instant

- Definition

Represents the fee payment required to extend the maturity date should the cash threshold be met through equity financings.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of facility fee paid by the company.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the increase in borrowing capacity on the line of credit facility.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Threshold amount which the Company must achieve from equity financings and, therefore, can elect to extend the maturity date of the loan.

+ References

No definition available.

+ Details

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Namespace Prefix:	insm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Unamortized discount from the issuance of warrants as of the report date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Name Regulation S-X (SX)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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-Subparagraph (SX 210.5-02.22(a)(1))

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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- Definition

Amount of the fee for available but unused credit capacity under the credit facility.

+ References

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-Publisher FASB

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-Topic 210

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-Number 210

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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-Name Regulation S-X (SX)

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+ Details

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- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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-Paragraph 3

-Subparagraph (SX 210.12-04.(a))

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

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Period Type:

Debt (Details) (USD $)	0 Months Ended
Debt (Details) (USD $)	Dec. 15, 2014	Mar. 31, 2015	Dec. 31, 2014	Jun. 29, 2012
Debt:
Notes payable		$ 25,000,000us-gaap_SecuredDebt
Accretion of end of term charge		333,000insm_AdditionalChargeAtEndOfTerm
Issuance fees paid to lender		(231,000)us-gaap_UnamortizedDebtIssuanceExpense
Discount from warrant		(113,000)insm_UnamortizedDiscountFromWarrant
Current portion of long-term debt		(24,989,000)us-gaap_DebtCurrent
Long-term debt			24,856,000us-gaap_LongTermDebtNoncurrent
Future principal repayments of the Notes
2016 (due in full January 1, 2016)		25,000,000
Total		25,000,000us-gaap_LongTermDebt
Loan and Security Agreement
Debt
Maximum borrowing capacity of term loan	25,000,000			20,000,000
Interest rate (as a percent)				9.25%
Commitment fee	25,000
Facility fee	125,000
Increase in borrowing capacity	5,000,000
Maturity date extension fee	250,000
Loan and Security Agreement \| Minimum
Debt
Amount of cash proceeds required to extend maturity date of loan	$ 90,000,000