Represents the period of the agreement under which the entity operates surface parking and garage parking spaces.

No definition available.

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

- Definition

Represents the amount of annual guaranteed minimum payments.

+ References

No definition available.

+ Details

Name:	sp_AnnualGuaranteedMinimumPayments
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	sp_CompensationAbstract
Namespace Prefix:	sp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of deficiency payment made by the entity during the period.

+ References

No definition available.

+ Details

Name:	sp_DeficiencyPaymentsMade
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of deficiency payments (net of repayments received) during the period.

+ References

No definition available.

+ Details

Name:	sp_DeficiencyPaymentsNetOfRepaymentsReceived
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of deficiency payment received by the entity during the period.

+ References

No definition available.

+ Details

Name:	sp_DeficiencyPaymentsReceived
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of accrued estimated deficiency payments that have met the criteria of being both probable and estimable during the period.

+ References

No definition available.

+ Details

Name:	sp_EstimatedAccruedDeficiencyPayments
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	sp_GainContingencyRollForward
Namespace Prefix:	sp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of interest income received on deficiency payments from the trustee.

+ References

No definition available.

+ Details

Name:	sp_InterestIncomeReceivedOnDeficiencyPayments
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the management fees recognized during the period.

+ References

No definition available.

+ Details

Name:	sp_ManagementFees
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the maximum percentage of premium on deficiency payments previously made, which the entity has a right to receive.

+ References

No definition available.

+ Details

Name:	sp_MaximumPremiumPercentageOnInitialDeficiencyPayment
Namespace Prefix:	sp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of garage parking spaces operated by the entity.

+ References

No definition available.

+ Details

Name:	sp_NumberOfGarageParkingSpacesOperated
Namespace Prefix:	sp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of management fee apportioned to the entity as per the agreement.

+ References

No definition available.

+ Details

Name:	sp_PercentageOfManagementFeeApportionedToEntity
Namespace Prefix:	sp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of management fee apportioned to an un-affiliated entity as per the agreement.

+ References

No definition available.

+ Details

Name:	sp_PercentageOfManagementFeeApportionedToUnaffiliatedEntity
Namespace Prefix:	sp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of premium income received on deficiency payments from the trustee.

+ References

No definition available.

+ Details

Name:	sp_PremiumIncomeReceivedOnDeficiencyPayments
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of annual principal and interest payments on revenue bonds.

+ References

No definition available.

+ Details

Name:	sp_RevenueBondsAnnualPrincipalAndInterestPayments
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the amount of cumulative management fees which have not been recognized.

+ References

No definition available.

+ Details

Name:	sp_UnrecognizedCumulativeManagementFees
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount or range of possible amounts of gain that could be realized upon the resolution of a contingency.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 30

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_GainContingenciesByNatureAxis=sp_BradleyReceivablesBradleyInternationalAirportParkingFacilitiesOperatingAgreementDeficiencyPaymentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=sp_BradleyInternationalAirportParkingFacilitiesOperatingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Bradley Agreement (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
Bradley Agreement (Details) $ in Thousands	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Deficiency payments
Deficiency payments
Balance at the beginning of the year			$ 13,327		$ 13,327
Deficiency payments made			101
Deficiency repayment received			(1,055)
Balance at the end of the year	$ 12,373		$ 12,373			$ 13,327
Bradley International Airport parking facilities operating agreement
Agreement
Agreement period with the State of Connecticut for operation of parking spaces			25 years
Number of garage parking spaces at Bradley International Airport operated \| item			3,500
Annual minimum guaranteed payment to the State by the trustee						10,815
Deficiency payments
Maximum premium percentage on initial deficiency payment			10.00%
Net deficiency repayment received (paid)	156	$ 24	$ 954	$ 1,074
Interest income on deficiency payment received from trustee	53	$ 134	309	134
Premium income on deficiency payment received from trustee			79	117
Estimated accrued deficiency payments	0		$ 0			0
Compensation
Management fee apportioned to the entity (as a percent)			60.00%
Management fee apportioned to an un-affiliated entity (as a percent)			40.00%
Unrecognized cumulative management fees	15,483		$ 15,483			$ 14,733
Management Fees			0	$ 0
Bradley International Airport parking facilities operating agreement \| Forecast
Agreement
Annual minimum guaranteed payment to the State by the trustee					$ 11,042
Bradley International Airport parking facilities operating agreement \| Minimum
Agreement
Annual minimum guaranteed payment to the State by the trustee			8,300
Bradley International Airport parking facilities operating agreement \| Maximum
Agreement
Annual minimum guaranteed payment to the State by the trustee			13,200
Bradley International Airport parking facilities operating agreement \| State of Connecticut special facility revenue bonds \| Minimum
Agreement
Annual principal and interest on revenue bonds	3,600		3,600
Bradley International Airport parking facilities operating agreement \| State of Connecticut special facility revenue bonds \| Maximum
Agreement
Annual principal and interest on revenue bonds	$ 4,500		$ 4,500