Revenue (Tables)

12 Months Ended

Dec. 31, 2020

Revenue from Contract with Customer [Abstract]

Summary of Contract Assets and Liabilities

The following table presents the beginning and ending balances of contract assets and contract liabilities:

(In thousands)	Contract Assets		Contract Liabilities
Beginning Balance, January 1, 2020	$	19,567	$	38,758
Ending Balance, December 31, 2020	$	17,697	$	28,641

Disaggregation of Revenue

The following table presents our revenue disaggregated by Market Segments as of December 31 as follows:

(In thousands)	2020		2019		2018
Aerospace Segment
Commercial Transport	$	262,636	$	523,921	$	536,269
Military	67,944		76,542		68,138
Business Jet	60,437		67,541		43,090
Other	26,971		24,605		28,128
Aerospace Total	417,988		692,609		675,625
Test Systems Segment
Semiconductor	3,483		9,692		84,254
Aerospace & Defense	81,116		70,401		43,377
Test Systems Total	84,599		80,093		127,631
Total	$	502,587	$	772,702	$	803,256

The following table presents our revenue disaggregated by Product Lines as of December 31 as follows:

(In thousands)	2020		2019		2018
Aerospace Segment
Electrical Power & Motion	$	179,245	$	338,237	$	303,180
Lighting & Safety	118,928		185,462		174,383
Avionics	76,113		106,787		131,849
Systems Certification	6,899		14,401		13,951
Structures	9,832		23,117		24,134
Other	26,971		24,605		28,128
Aerospace Total	417,988		692,609		675,625
Test Systems	84,599		80,093		127,631
Total	$	502,587	$	772,702	$	803,256