Special Charges (Announced Restructuring Charges (Recoveries)) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	$ 5,186	$ 5,434
2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		2,480
2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			$ 2,263
Facility Closing [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	1,423	1,964
Facility Closing [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		366
Facility Closing [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			2
Employee Severance [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	6,609	3,470
Employee Severance [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		2,114
Employee Severance [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			2,261
Energy Segment | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	(1,181)	3,516
Energy Segment | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		222
Energy Segment | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			988
Energy Segment | Facility Closing [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	(1,785)	1,964
Energy Segment | Facility Closing [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		0
Energy Segment | Facility Closing [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			(92)
Energy Segment | Employee Severance [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	604	1,552
Energy Segment | Employee Severance [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		222
Energy Segment | Employee Severance [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			1,080
Aerospace and Defense Segment [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	595	382
Aerospace and Defense Segment [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		2,258
Aerospace and Defense Segment [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			1,275
Aerospace and Defense Segment [Member] | Facility Closing [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	35	0
Aerospace and Defense Segment [Member] | Facility Closing [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		366
Aerospace and Defense Segment [Member] | Facility Closing [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			94
Aerospace and Defense Segment [Member] | Employee Severance [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	560	382
Aerospace and Defense Segment [Member] | Employee Severance [Member] | 2017 Actions Restructuring Charges [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date		1,892
Aerospace and Defense Segment [Member] | Employee Severance [Member] | 2016 Actions Restructuring Charges (Recoveries) [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date			$ 1,181
Industrial Segment [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	5,772	1,536
Industrial Segment [Member] | Facility Closing [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	327	0
Industrial Segment [Member] | Employee Severance [Member] | 2018 Actions Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring related special charges - incurred to date	$ 5,445	$ 1,536