Summary of Significant Accounting Policies - Summary of Deferred Tax Assets and Liability (Parenthetical) (Detail)	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Federal statutory tax rate used to calculate provisional effect of the Tax Reform Act in the period of enactment	21.00%

Percentage of domestic federal statutory tax rate used to calculate effect of the Tax Cuts and Jobs Act of 2017 in the period of enactment.

No definition available.

Name:	kaac_TaxCutsAndJobsActOf2017IncompleteAccountingTaxRateEffectOfTaxLawChangesInPeriodOfEnactmentPercent
Namespace Prefix:	kaac_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration