XML 46 R67.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Significant Accounting Policies - Investments in Unconsolidated Joint Ventures/Deferred Lease Costs/Revenue Recognition/Income Taxes (Details) $ / shares in Units, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) joint_venture $ / shares | Dec. 31, 2018 USD ($) $ / shares | Dec. 31, 2017 USD ($) $ / shares
Schedule of Equity Method Investments [Line Items] |  |  |
Number of joint ventures with performance guarantees under master leases | joint_venture | 1 |  |
Deferred Lease Costs [Abstract] |  |  |
Portion of compensation capitalized | $ | $ 6.3 | $ 15.7 | $ 16.4
Estimated average lease term (in years) | 8 years |  |
Days past due for income recognition on debt and preferred equity investments to be suspended | 90 days |  |
Income taxes |  |  |
Federal, state and local tax provision | $ | $ 1.5 | $ 2.8 | $ 4.3
Dividends per share paid (in dollars per share) | $ 3.40 | $ 3.25 | $ 3.10
Ordinary Income Dividend |  |  |
Income taxes |  |  |
Dividends per share paid (in dollars per share) | 2.59 | 1.46 | 1.24
Capital Gains Dividend |  |  |
Income taxes |  |  |
Dividends per share paid (in dollars per share) | $ 0.81 | $ 1.79 | $ 1.86

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | slg_DeferredLeaseCostsAbstract
Namespace Prefix: | slg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the amount of deferred lease costs capitalized during the period. + References No definition available. + Details
Name: | slg_DeferredLeaseCostsCapitalizedInPeriod
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of days by which payments become past due, at which income recognition on financing receivables is generally suspended. + References No definition available. + Details
Name: | slg_FinancingReceivableNumberOfDaysPastDueForSuspendingIncomeRecognition
Namespace Prefix: | slg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Joint Ventures with Performance Guarantees under Master Leases + References No definition available. + Details
Name: | slg_NumberofJointVentureswithPerformanceGuaranteesunderMasterLeases
Namespace Prefix: | slg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the estimated average term of the operating leases. + References No definition available. + Details
Name: | slg_OperatingLeasesEstimatedAverageLeaseTerm
Namespace Prefix: | slg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate dividends paid during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_CommonStockDividendsPerShareCashPaid
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_IncomeTaxDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Details
Name: | us-gaap_DividendsAxis=slg_OrdinaryIncomeDividendMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=slg_CapitalGainsDividendMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |