Trigger for change in control for purposes of senior revolving credit facility, as a percentage

No definition available.

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- Definition

The initial issuance price at which a debt instrument was offered, stated as a percentage.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Debt Instrument, Interest Rate, Potential Reduction in Rate if Certain Leverage Ratios are Met

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Debt Instrument, Interest Rate, Potential Reduction in Rate if Certain Leverage Ratios are Met, Per Reduction

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Debt Instrument, Interest Rate, Potential Reductions in Interest Rate

+ References

No definition available.

+ Details

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- Definition

Amount by which the contractual interest rate for funds borrowed is less than the interest rate for funds borrowed on previously outstanding debt.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Periodic Payment, Quarterly Principal Payments

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Periodic Payment, Quarterly Principal Payments, Year Five

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Periodic Payment, Quarterly Principal Payments, Year Four

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Periodic Payment, Quarterly Principal Payments, Year One

+ References

No definition available.

+ Details

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Namespace Prefix:	lgfa_
Data Type:	num:percentItemType
Balance Type:	na
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- Definition

Debt Instrument, Periodic Payment, Quarterly Principal Payments, Year Three

+ References

No definition available.

+ Details

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Namespace Prefix:	lgfa_
Data Type:	num:percentItemType
Balance Type:	na
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- Definition

Debt Instrument, Periodic Payment, Quarterly Principal Payments, Year Two

+ References

No definition available.

+ Details

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Namespace Prefix:	lgfa_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Prepayment Premium

+ References

No definition available.

+ Details

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Namespace Prefix:	lgfa_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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

- Details

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- Details

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- Details

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- Details

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Debt (Narrative - Senior Credit Facilities) (Details) $ in Millions		3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 11, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) reduction	Mar. 31, 2017	Dec. 12, 2017 USD ($)	Dec. 08, 2016 USD ($)
Line of Credit Facility [Abstract]
Term loan B facility, initial issuance price, percentage						99.50%
Loss on extinguishment of debt associated with other voluntary prepayments of Term Loan B/Term Loan B-1		$ 1.8	$ 19.8
Revolving Credit Facility
Line of Credit Facility [Abstract]
Debt instrument, term			5 years
Revolving credit facility, maximum borrowing capacity		1,000.0	$ 1,000.0			$ 1,000.0
Revolving credit facility, available amount		$ 1,000.0	$ 1,000.0
Number of possible reductions in margin \| reduction			2
Effective interest rate		3.56%	3.56%
Change in control, trigger percentage		50.00%	50.00%
Letter of Credit
Line of Credit Facility [Abstract]
Letters of credit outstanding, amount		$ 0.0	$ 0.0
Minimum \| Revolving Credit Facility
Line of Credit Facility [Abstract]
Revolving credit facility, commitment fee annual percentage			0.25%
Maximum \| Revolving Credit Facility
Line of Credit Facility [Abstract]
Revolving credit facility, commitment fee annual percentage			0.375%
Base Rate \| Revolving Credit Facility
Line of Credit Facility [Abstract]
Basis spread on variable interest rate				1.50%
LIBOR \| Revolving Credit Facility
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			2.00%	2.50%
Potential reduction in interest rate if certain leverage ratios are met, total			0.50%
Potential reduction in interest rate if certain leverage ratios are met, per reduction			0.25%
Term Loan A Facility \| Term Loan
Line of Credit Facility [Abstract]
Principal amount issued						1,000.0
Debt instrument, term			5 years
Number of possible reductions in margin \| reduction			2
Effective interest rate		3.56%	3.56%
Quarterly principal payment percent, year one		1.25%	1.25%
Quarterly principal payment percent, year two		1.25%	1.25%
Quarterly principal payment percent, year three		1.75%	1.75%
Quarterly principal payment percent, year four		2.50%	2.50%
Quarterly principal payment percent, year five		2.50%	2.50%
Term Loan A Facility \| Base Rate \| Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			1.50%
Term Loan A Facility \| LIBOR \| Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			2.50%
Potential reduction in interest rate if certain leverage ratios are met, total			0.50%
Potential reduction in interest rate if certain leverage ratios are met, per reduction			0.25%
Term Loan B Facility \| Term Loan
Line of Credit Facility [Abstract]
Principal amount issued	$ 925.0				$ 900.0	$ 2,000.0
Debt instrument, term			7 years
Principal amount of voluntary prepayment	$ 25.0	$ 75.0
Effective interest rate		3.81%	3.81%
Quarterly principal payment percent		0.25%	0.25%
Prepayment premium percent		1.00%	1.00%
Term Loan B Facility \| Base Rate \| Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate	2.00%
Term Loan B Facility \| LIBOR \| Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate	3.00%
Term Loan B Facility \| LIBOR \| Minimum \| Term Loan
Line of Credit Facility [Abstract]
Coupon rate	0.75%
Term Loan B-1 Facility \| Term Loan
Line of Credit Facility [Abstract]
Principal amount issued	$ 900.0
Debt instrument, term			6 years
Percentage (per annum) by which the applicable margin under Term Loan B-1 is less than the margin under the Term Loan B		0.75%	0.75%
Term Loan B-1 Facility \| Base Rate \| Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			1.25%
Term Loan B-1 Facility \| LIBOR \| Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			2.25%
Term Loan B-1 Facility \| LIBOR \| Minimum \| Term Loan
Line of Credit Facility [Abstract]
Coupon rate		0.75%	0.75%
Term Loan B and Term Loan B-1
Line of Credit Facility [Abstract]
Loss on extinguishment of debt associated with other voluntary prepayments of Term Loan B/Term Loan B-1		$ 1.8	$ 19.8
Term Loan B and Term Loan B-1 \| Term Loan
Line of Credit Facility [Abstract]
Principal amount of voluntary prepayment			$ 740.0