Aggregate Tender Amount

No definition available.

Name:	spr_AggregateTenderAmount
Namespace Prefix:	spr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

[Line Items] for Debt Type [Table]

+ References

No definition available.

+ Details

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Namespace Prefix:	spr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

+ Details

Name:	spr_LongTermDebtAndCapitalLeaseObligationsCurrentAndNonCurrentAbstract
Namespace Prefix:	spr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Optional Revolver Commitment

+ References

No definition available.

+ Details

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Namespace Prefix:	spr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
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-Section S99
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+ Details

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

- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid more than one year (or one operating cycle, if longer) after the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
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+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_DebtDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
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

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateTerms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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+ Details

Name:	us-gaap_DebtInstrumentPaymentTerms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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+ Details

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

- Definition

Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

+ References

+ Details

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

- Definition

Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

+ References

+ Details

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

- Definition

Amount of long-term debt classified as other, payable within one year or the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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

- Definition

Amount of long-term debt classified as other, payable after one year or the operating cycle, if longer.

+ References

+ Details

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

- Definition

Carrying value as of the balance sheet date of the portion of long-term, collateralized debt obligations due within one year or the operating cycle, if longer. Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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+ Details

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

- Definition

Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

+ References

+ Details

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

- Definition

Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

+ Details

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

- Definition

Carrying value as of the balance sheet date of the portion of long-term notes having the highest claim on the assets of the issuer in case of bankruptcy or liquidation, due within one year or the normal operating cycle, if longer. Senior note holders are paid off in full before any payments are made to debt holders having a lesser priority of repayment.

+ References

+ Details

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

- Definition

Carrying value as of the balance sheet date of the portion of long-term, uncollateralized debt obligations due within one year or the normal operating cycle, if longer.

+ References

+ Details

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

- Definition

Carrying value as of the balance sheet date of uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ References

+ Details

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

- Details

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Period Type:

- Details

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- Details

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Period Type:

- Details

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- Details

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- Details

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- Details

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Period Type:

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Debt (Details) - USD ($) $ in Millions	9 Months Ended
Debt (Details) - USD ($) $ in Millions	Sep. 27, 2018	Dec. 31, 2017	Jun. 01, 2016
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Capital Lease Obligations, Current	$ 6.9	$ 5.2
Capital Lease Obligations, Noncurrent	36.3	33.6
Other Long-term Debt, Current	1.0	1.0
Other Long-term Debt, Noncurrent	58.6	58.5
Long-term Debt and Capital Lease Obligations, Current	25.0	31.1
Long-term Debt and Capital Lease Obligations	1,869.7	1,119.9
Optional Revolver Commitment	750.0
Secured Debt Term A [Member]
Debt Disclosure [Abstract]
Secured Debt, Current		24.9
Secured Long-term Debt, Noncurrent		435.8
Debt Type [Line Items]
Unsecured Debt	17.1
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Gain (Loss) on Extinguishment of Debt	1.3
Unsecured Long-term Debt, Noncurrent	187.8
Senior unsecured notes due 2022 [Member]
Debt Type [Line Items]
Extinguishment of Debt, Amount	300.0
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Senior Notes, Current	0.0	0.0
Senior Notes, Noncurrent	0.0	294.8
Debt Instrument, Repurchase Amount	202.6
Incremental Tender Amount	97.4
Gain (Loss) on Extinguishment of Debt	13.2
Senior Unsecured Notes Due 2026 [Member]
Debt Type [Line Items]
Debt Instrument, Face Amount			$ 300.0
Debt Instrument, Interest Rate, Stated Percentage			3.85%
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Senior Notes, Current	0.0	0.0
Senior Notes, Noncurrent	297.5	297.2
Senior Unsecured Notes Due 2021 [Member]
Debt Type [Line Items]
Debt Instrument, Face Amount	$ 300.0
Debt Instrument, Interest Rate Terms	The Floating Rate Notes bear interest at a rate per annum equal to three-month LIBOR, as determined in the case of the initial interest period, on May 25, 2018, and thereafter at the beginning of each quarterly period as described herein, plus 80 basis points and mature on June 15, 2021. Interest on the Floating Rate Notes is payable on March 15, June 15, September 15 and December 15 of each year, beginning on September 15, 2018.
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Senior Notes, Current	$ 0.0	0.0
Senior Notes, Noncurrent	298.4	0.0
Senior Unsecured Notes Due 2023 [Member]
Debt Type [Line Items]
Debt Instrument, Face Amount	$ 300.0
Debt Instrument, Interest Rate, Stated Percentage			3.95%
Debt Instrument, Interest Rate Terms	The 2023 Notes bear interest at a rate of 3.950% per annum and mature on June 15, 2023
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Senior Notes, Current	$ 0.0	0.0
Senior Notes, Noncurrent	297.8	0.0
Senior Unsecured Notes Due 2028 [Member]
Debt Type [Line Items]
Debt Instrument, Face Amount	$ 700.0
Debt Instrument, Interest Rate, Stated Percentage			4.60%
Debt Instrument, Interest Rate Terms	The 2028 Notes bear interest at a rate of 4.600% per annum and mature on June 15, 2028.
Long Term Debt And Capital Lease Obligations Current And Non Current [Abstract]
Senior Notes, Current	$ 0.0	0.0
Senior Notes, Noncurrent	$ 693.3	$ 0.0
2018 Revolver, 2018 Term Loan, Delayed Term Loan [Member]
Debt Type [Line Items]
Debt Instrument, Interest Rate Terms	Each of the 2018 Revolver, the 2018 Term Loan and the Delayed Draw Term Loan matures July 12, 2023, and bears interest, at Spirit’s option, at either LIBOR plus 1.375% or a defined “base rate” plus 0.375%, subject to adjustment to between LIBOR plus 1.125% and LIBOR plus 1.875% (or between base rate plus 0.125% and base rate plus 0.875%, as applicable) based on changes to Spirit’s senior unsecured debt rating provided by Standard & Poor’s Financial Services LLC and/or Moody’s Investors Service, Inc.
Debt Instrument, Payment Terms	The principal obligations under the Delayed Draw Term Loan are to be repaid in equal quarterly installments of 1.25% of the outstanding principal amount of the Delayed Draw Term Loan as of March 31, 2019, subject to adjustments for any extension of the availability period of the Delayed Draw Term Loan, with the balance due at maturity of the Delayed Draw Term Loan.
Senior Unsecured Notes due 2023 and 2028 [Member]
Debt Type [Line Items]
Debt Instrument, Payment Terms	Interest on the 2023 Notes and 2028 Notes is payable on June 15 and December 15 of each year, beginning on December 15, 2018.