XML 27 R50.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Schedule III: Rollforward of Real Estate Assets and Accumulated Depreciation (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Reconciliation Of Carrying Amount Of Real Estate Investments RollForward [Line Items] |  |  |
Balance at the beginning of period | $ 1,050,291 | $ 1,025,234 | $ 967,975
Less: Fully depreciated assets | (14) | (381) | (3,471)
Balance at the end of the period | 1,062,208 | 1,050,291 | 1,025,234
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward] |  |  |
Balance at the beginning of period | 157,232 | 132,386 | 114,235
Real Estate Accumulated Depreciation, Depreciation Expense | 27,655 | 25,227 | 21,622
Less: Fully depreciated assets | (14) | (381) | (3,471)
Balance at the end of the period | 184,873 | 157,232 | 132,386
Land Improvements [Member] |  |  |
Reconciliation Of Carrying Amount Of Real Estate Investments RollForward [Line Items] |  |  |
Real Estate, Improvements | 0 | 0 | 0
Building Improvements [Member] |  |  |
Reconciliation Of Carrying Amount Of Real Estate Investments RollForward [Line Items] |  |  |
Real Estate, Improvements | 50,869 | 102,402 | 238,119
Construction in Progress [Member] |  |  |
Reconciliation Of Carrying Amount Of Real Estate Investments RollForward [Line Items] |  |  |
Real Estate, Improvements | $ (38,938) | $ (76,964) | $ (177,389)

X
- Details
Name: | alx_ReconciliationOfCarryingAmountOfRealEstateInvestmentsRollforwardLineItems
Namespace Prefix: | alx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount as of the balance sheet date of accumulated depreciation pertaining to real estate properties. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.FN4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674 + Details
Name: | us-gaap_RealEstateAccumulatedDepreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of depreciation expense for the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.FN4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674 + Details
Name: | us-gaap_RealEstateAccumulatedDepreciationDepreciationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Decreases or increases in accumulated depreciation for the period other than deductions attributed to real estate sold or written-off. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.FN4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674 + Details
Name: | us-gaap_RealEstateAccumulatedDepreciationOtherDeductions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Gross amount of real estate as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674 + Details
Name: | us-gaap_RealEstateGrossAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of improvements made to real estate investments during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674 + Details
Name: | us-gaap_RealEstateImprovements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total other decrease (increase) in the carrying amount of real estate investments during the period other than cost of real estate sold. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 970 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-28.4) -URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph c -Subparagraph Schedule III -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 28 -Article 12 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 10 -Section S99 -Paragraph 6 -Subparagraph (SX 210.5-04.(c) Schedule III) -URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674 + Details
Name: | us-gaap_RealEstateOtherDeductions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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