Name:	sp_DeferredCompensationArrangementWithIndividualMinimumContractualPeriodForAnnualPaymentsToExecutives
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the age at which an employee is eligible to receive a defined monthly benefit under the plan.

No definition available.

Name:	sp_DefinedBenefitPlanEligibilityAge
Namespace Prefix:	sp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (d)
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
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Name:	us-gaap_CashSurrenderValueOfLifeInsurance
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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Name:	us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense
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Data Type:	xbrli:monetaryItemType
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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.

No definition available.

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
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-Topic 325
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans.

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-Paragraph 1
-Subparagraph (SX 210.9-03(15))
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(15))
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