XML 58 R83.htm IDEA: XBRL DOCUMENT v2.4.1.9
Share and Unit-Based Plans: Long-Term Incentive Plan Units (Details) (USD $)
12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Feb. 11, 2013
Jan. 31, 2013
Jan. 16, 2013
Jan. 12, 2015
Mar. 07, 2014
Sep. 01, 2013
Feb. 15, 2013
Apr. 16, 2012
Feb. 23, 2012
Dec. 31, 2013
Stock units                          
Share and unit-based plans                          
Conversion rate 1mac_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsConversionRate
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
                       
Granted (in shares) 75,309us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
67,920us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
72,322us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
                   
Granted (in shares) $ 60.50us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
$ 62.01us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
$ 54.43us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
                   
Vested (in shares) 68,253us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
45,279us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
533,985us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_StockUnitsMember
                   
LTIP units                          
Share and unit-based plans                          
Conversion rate 1mac_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsConversionRate
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
                       
Granted (in shares) 725,908us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
332,189us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
315,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
                   
Granted (in shares) $ 51.71us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
$ 66.58us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
$ 40.53us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
                   
Absolute return requirement (in shares) 3.00%mac_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsotherthanOptionsAbsoluteReturnRequirement
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
                       
Level of percentile ranking at which awards vested (as a percent)       100.00%mac_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentileRankingOfAwardsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
  96.00%mac_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentileRankingOfAwardsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
             
Vested (in shares) 679,213us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
518,900us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
305,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
  200,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
318,900us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
             
Forfeited (in shares) 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
13,289us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
    13,289us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
             
LTIP units | Subsequent Event                          
Share and unit-based plans                          
Level of percentile ranking at which awards vested (as a percent)             150.00%mac_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentileRankingOfAwardsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
           
Long Term Incentive Plan, Market Indexed                          
Share and unit-based plans                          
Vested (in shares) 136,465us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMarketIndexedMember
                       
Executive Officer | LTIP units                          
Share and unit-based plans                          
Granted (in shares)                 20,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
332,189us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
10,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
190,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
 
Granted (in shares)               $ 60.25us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
$ 59.57us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
$ 66.58us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
$ 54.97us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
$ 37.77us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
 
Executive Officer | LTIP units | 2014 LTIP Units Series 1                          
Share and unit-based plans                          
Granted (in shares)               246,471us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_PlanNameAxis
= mac_A2014LTIPUnitsSeries1Member
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
        272,930us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_PlanNameAxis
= mac_A2014LTIPUnitsSeries1Member
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
Granted (in shares)                         $ 45.34us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_PlanNameAxis
= mac_A2014LTIPUnitsSeries1Member
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
Executive Officer | LTIP units | 2014 LTIP Units Series 2                          
Share and unit-based plans                          
Granted (in shares)                         70,042us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_PlanNameAxis
= mac_A2014LTIPUnitsSeries2Member
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember
Granted (in shares)                         $ 58.89us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= mac_LongTermIncentivePlanMember
/ us-gaap_PlanNameAxis
= mac_A2014LTIPUnitsSeries2Member
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ExecutiveOfficerMember