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Share and Unit-Based Plans - Narrative (Details) (USD $) In Thousands, except Share data, unless otherwise specified | 3 Months Ended | 0 Months Ended
--- | --- | ---
Mar. 31, 2015 | Mar. 31, 2014 | Mar. 06, 2015 | Jan. 01, 2015
Share and unit-based plans |  |  |  |
Capitalized share and unit-based compensation costs | $ 4,347 us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount | $ 3,841 us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount |  |
Stock units |  |  |  |
Share and unit-based plans |  |  |  |
Conversion rate of shares | 1 mac_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsConversionRate / us-gaap_AwardTypeAxis = mac_StockUnitsMember |  |  |
Granted (in shares) | 75,171 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = mac_StockUnitsMember |  |  |
Average grant date fair value (in dollars per share) | $ 86.72 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = mac_StockUnitsMember |  |  |
Unrecognized compensation cost of share and unit-based plans | 6,107 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = mac_StockUnitsMember |  |  |
LTIP Units |  |  |  |
Share and unit-based plans |  |  |  |
Conversion rate of shares | 1 mac_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsConversionRate / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember |  |  |
Granted (in shares) | 368,508 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember |  |  |
Average grant date fair value (in dollars per share) | $ 75.98 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember |  |  |
Share-based Compensation Arrangement by Share-based Payment Award Equity Instruments other than Options, Absolute Return Requirement | 3.00%mac_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsotherthanOptionsAbsoluteReturnRequirement / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember |  |  |
Unrecognized compensation cost of share and unit-based plans | 15,522 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember |  |  |
Stock awards |  |  |  |
Share and unit-based plans |  |  |  |
Granted (in shares) | 0 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = mac_StockAwardsMember |  |  |
Average grant date fair value (in dollars per share) | $ 0.00 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = mac_StockAwardsMember |  |  |
Unrecognized compensation cost of share and unit-based plans | 174 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = mac_StockAwardsMember |  |  |
Stock options |  |  |  |
Share and unit-based plans |  |  |  |
Unrecognized compensation cost of share and unit-based plans | 39 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember |  |  |
Phantom stock units |  |  |  |
Share and unit-based plans |  |  |  |
Granted (in shares) | 3,185 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = us-gaap_PhantomShareUnitsPSUsMember |  |  |
Average grant date fair value (in dollars per share) | $ 84.97 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_PhantomShareUnitsPSUsMember |  |  |
Unrecognized compensation cost of share and unit-based plans | $ 500 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = us-gaap_PhantomShareUnitsPSUsMember |  |  |
Executive Officer | LTIP Units |  |  |  |
Share and unit-based plans |  |  |  |
Average grant date fair value (in dollars per share) |  |  | $ 86.72 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember / us-gaap_TitleOfIndividualAxis = us-gaap_ExecutiveOfficerMember |
2016 LTIP Units Series 1 | Executive Officer | LTIP Units |  |  |  |
Share and unit-based plans |  |  |  |
Granted (in shares) |  |  |  | 49,451 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember / us-gaap_PlanNameAxis = mac_A2015LTIPUnitsSeries1Member / us-gaap_TitleOfIndividualAxis = us-gaap_ExecutiveOfficerMember
Average grant date fair value (in dollars per share) |  |  |  | $ 83.41 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember / us-gaap_PlanNameAxis = mac_A2015LTIPUnitsSeries1Member / us-gaap_TitleOfIndividualAxis = us-gaap_ExecutiveOfficerMember
2015 LTIP Units Series 2 [Member] | Executive Officer | LTIP Units |  |  |  |
Share and unit-based plans |  |  |  |
Granted (in shares) |  |  |  | 186,450 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember / us-gaap_PlanNameAxis = mac_A2015LTIPUnitsSeries2Member / us-gaap_TitleOfIndividualAxis = us-gaap_ExecutiveOfficerMember
Average grant date fair value (in dollars per share) |  |  |  | $ 66.37 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember / us-gaap_PlanNameAxis = mac_A2015LTIPUnitsSeries2Member / us-gaap_TitleOfIndividualAxis = us-gaap_ExecutiveOfficerMember
2015 LTIP Units Series 3 | Executive Officer | LTIP Units |  |  |  |
Share and unit-based plans |  |  |  |
Granted (in shares) |  |  | 132,607 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod / us-gaap_AwardTypeAxis = mac_LongTermIncentivePlanMember / us-gaap_PlanNameAxis = mac_A2015LTIPUnitsSeries3Member / us-gaap_TitleOfIndividualAxis = us-gaap_ExecutiveOfficerMember |

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- Definition Share-based Compensation Arrangement by Share-based Payment Award Equity Instruments other than Options, Absolute Return Requirement + References No definition available. + Details
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- Definition Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments, Other than Options, Conversion Rate + References No definition available. + Details
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- Definition Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Unrecognized cost of unvested share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- 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://www.xbrl.org/2003/role/presentationRef -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=6415400&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued 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://www.xbrl.org/2003/role/presentationRef -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=6415400&loc=d3e5070-113901 + Details
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