Health insurance expense.

No definition available.

Name:	ibp_HealthInsuranceExpense
Namespace Prefix:	ibp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Pension plans, postretirement and other employee benefits.

+ References

No definition available.

+ Details

Name:	ibp_PensionPlansPostretirementAndOtherEmployeeBenefitsLineItems
Namespace Prefix:	ibp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of equal installments for vesting restricted stock.

+ References

No definition available.

+ Details

Name:	ibp_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEqualInstallmentsForVestingOfStockAwards
Namespace Prefix:	ibp_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

All expenses associated with Worker's Compensation Insurance benefits incurred during the period.

+ References

No definition available.

+ Details

Name:	ibp_WorkersCompensationExpense
Namespace Prefix:	ibp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Definition

Amount of administrative expense incurred by defined contribution plan.

+ References

No definition available.

+ Details

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

- Definition

Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=ibp_PerformanceBasedRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=ibp_TwoThousandAndFourteenOmnibusIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=ibp_NonPerformanceBasedAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=us-gaap_OfficerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=us-gaap_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_DefinedBenefitPostretirementHealthCoverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Benefits - Additional Information (Detail) pure in Millions		3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Installments shares	Sep. 30, 2017 USD ($) Installments shares	Dec. 31, 2017 USD ($)
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Healthcare benefit expense, net of employee contributions		$ 4,500,000	$ 4,100,000	$ 13,300,000	$ 12,400,000
Accrued compensation	$ 25,370,000	25,370,000		25,370,000		$ 25,399,000
Administration expense related to employee contribution plan		300,000	400,000	1,200,000	1,300,000
Share-based compensation expense		1,893,000	2,179,000	6,089,000	4,749,000
Unrecognized compensation expense	$ 6,100,000	6,100,000		6,100,000
Compensation cost not yet recognized, period for recognition	1 year 10 months 24 days
Cost of Sales [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Workers' compensation expense		4,400,000	3,100,000	9,700,000	9,800,000
Share-based compensation expense		94,000	507,000	749,000	507,000
Administrative [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based compensation expense		1,769,000	1,380,000	$ 4,938,000	3,950,000
Performance Based Restricted Stock Units [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Number of shares granted \| shares				14,072
Share-based compensation expense		300,000	1,000,000	$ 1,500,000	$ 1,700,000
Unrecognized compensation expense	$ 400,000	400,000		$ 400,000
Compensation cost not yet recognized, period for recognition	6 months
2014 Omnibus Incentive Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Number of shares granted \| shares				100,000	100,000
Number of equal installments for common stock \| Installments				3	3
Number of shares surrendered to satisfy tax withholding obligations \| shares				41,000	10,000
Share based compensation, recognized tax benefits		0	0	$ 500,000	$ 600,000
2014 Omnibus Incentive Plan [Member] \| Non-Performance-Based Awards [Member] \| Administrative [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based compensation expense		1,000,000	800,000	$ 2,900,000	1,900,000
2014 Omnibus Incentive Plan [Member] \| Officer [Member] \| Performance Shares [Member] \| Common Stock [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Number of shares granted \| shares				2
Share-based compensation expense		600,000	$ 300,000	$ 1,600,000	$ 700,000
Number of equal installments for common stock				0.1
2014 Omnibus Incentive Plan [Member] \| Officer [Member] \| Performance Based Restricted Stock Units [Member] \| Common Stock [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Unrecognized compensation expense	$ 3,600,000	3,600,000		$ 3,600,000
Compensation cost not yet recognized, period for recognition	1 year 9 months 18 days
2014 Omnibus Incentive Plan [Member] \| Directors [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Number of shares granted \| shares				5,000	6,000
Common stock vesting period				1 year
Share-based compensation expense		25,000		$ 100,000	$ 300,000
Medical IBNR Included in Accrued Compensation [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Accrued compensation	$ 2,100,000	$ 2,100,000		$ 2,100,000		$ 1,900,000