Summary of Significant Accounting Policies - Percentage of revenue from U.S. government contracts (Details)	12 Months Ended
Dec. 31, 2016
New Accounting Pronouncements
Revenues from contracts with U.S. Government (as a percent)	25.00%

Percentage of revenue from contracts with U.S. Government that will be impacted by the new revenue recognition standard.

No definition available.

Name:	txt_RevenuesFromContractsWithU.S.GovernmentPercentage
Namespace Prefix:	txt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration