Accounting Policies (Details)	Sep. 30, 2016
Accounting Policies [Abstract]
Percentage of cash and cash equivalents held by the Company's foreign subsidiaries outside the United States	83.00%

Percentage of cash and cash equivalents maintained outside of the United States. At the balance sheet date, the percentage of cash and cash equivalents held by the Company's foreign subsidiaries.

No definition available.

Name:	ca_PercentageOfCashAndCashEquivalentsHeldByCompanysForeignSubsidiaries
Namespace Prefix:	ca_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant