Principal Assumptions of Esterline, CMC and Other Non-U.S. Plans (Detail)	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017
Minimum
Defined Benefit Plan Disclosure [Line Items]
Assumed long-term rate of return on plan assets	3.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Assumed long-term rate of return on plan assets	7.50%
Pension Plan | Minimum | Other Non-U.S. Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.50%	1.40%
Rate of increase in future compensation levels	3.20%	2.96%
Assumed long-term rate of return on plan assets	3.00%	3.25%
Pension Plan | Maximum | Other Non-U.S. Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	9.75%	8.75%
Rate of increase in future compensation levels	10.31%	10.29%
Assumed long-term rate of return on plan assets	7.50%	8.25%
Esterline U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.35%	3.75%
Rate of increase in future compensation levels	4.48%	4.48%
Assumed long-term rate of return on plan assets	7.00%	7.00%
Esterline U.S. Plans | Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.35%	3.75%
Initial weighted average health care trend rate	6.00%	6.00%
Ultimate weighted average health care trend rate	6.00%	6.00%
CMC Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.84%	3.76%
Rate of increase in future compensation levels	2.75%	2.75%
Assumed long-term rate of return on plan assets	5.34%	5.19%
CMC Plans | Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.48%	3.51%
Initial weighted average health care trend rate	5.70%	5.80%
Ultimate weighted average health care trend rate	4.10%	4.10%