Quarterly Financial Data (Details Textuals) $ in Millions	3 Months Ended
Sep. 30, 2015 USD ($)
Disclosure Of Quarterly Financial Data [Abstract]
Out of period spot valuation adjustment	$ 20.1

Impact related to out of period corrections in the prior period financial statements with no impact on current period financial statements.

No definition available.

Name:	aexc_ImmaterialErrorCorrectionSpotValuation
Namespace Prefix:	aexc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration