Operating Segments and Related Information (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 489,044	$ 471,248	$ 481,998	$ 444,736	$ 448,463	$ 434,898	$ 452,707	$ 439,618	$ 1,887,026	$ 1,775,686	$ 1,800,434
Intersegment revenue									0	0	0
Earnings (loss) from operations									273,260	318,606	289,961
Industrial
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									737,656	717,882	672,120
Intersegment revenue									16,510	19,482	21,747
Earnings (loss) from operations									240,847	216,880	199,903
Government and defense
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									794,941	663,436	629,147
Intersegment revenue									5,507	11,409	11,283
Earnings (loss) from operations									207,430	199,702	179,160
Commercial
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									354,429	394,368	499,167
Intersegment revenue									19,177	20,056	14,942
Earnings (loss) from operations									45,679	57,399	56,066
Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue									41,194	50,947	47,972
Total Segments [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue										1,775,686
Earnings (loss) from operations									$ 493,956	$ 473,981	$ 435,129