Income Taxes - Narrative (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)
Income Tax Disclosure [Abstract]
Remeasured ending deferred tax asset	$ 14,189

Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense (Benefit)

No definition available.

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Namespace Prefix:	mac_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration