Principal Assumptions of Esterline, CMC and Other Non-U.S. Plans (Detail)	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Minimum
Defined Benefit Plan Disclosure [Line Items]
Assumed long-term rate of return on plan assets	3.25%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Assumed long-term rate of return on plan assets	8.25%
Pension Plan | Minimum | Other Non-U.S. Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.40%	0.90%
Rate of increase in future compensation levels	2.96%	2.96%
Assumed long-term rate of return on plan assets	3.25%	3.25%
Pension Plan | Maximum | Other Non-U.S. Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	8.75%	7.75%
Rate of increase in future compensation levels	10.29%	10.13%
Assumed long-term rate of return on plan assets	8.25%	8.00%
Esterline U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.75%	3.60%
Rate of increase in future compensation levels	4.48%	4.28%
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	3.75%	3.60%
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	3.76%	3.22%
Rate of increase in future compensation levels	2.75%	2.75%
Assumed long-term rate of return on plan assets	5.19%	5.66%
CMC Plans | Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.51%	3.16%
Initial weighted average health care trend rate	5.80%	6.00%
Ultimate weighted average health care trend rate	4.10%	4.20%