Supplemental Retirement Plan and Related Post Retirement Benefits - Additional Information (Detail)

v2.4.1.9

Supplemental Retirement Plan and Related Post Retirement Benefits - Additional Information (Detail)	3 Months Ended
	Apr. 04, 2015 RetirementPlans
Compensation and Retirement Disclosure [Abstract]
Number of non-qualified supplemental retirement defined benefit plans	2atro_NumberOfNonQualifiedSupplementalRetirementDefinedBenefitPlans