Summary of Significant Accounting Policies (Revenue Recognition) (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Remaining Performance Obligation, Amount		$ 986,100
Revenues		$ 1,875,425	$ 1,805,909	$ 1,808,376
Inventory Write-down	$ 32,500
Percentage of pre-contract inventory (less than)		1.00%	1.00%
Performance obligations satisfied in previous periods [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues		$ 6,700
Aerospace
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues		$ 735,994	$ 724,944	702,054
Decrease to operating income from the quarterly impact of revisions in long term contracts				$ (800)
Increase to operating income from quarterly impact of revisions in long term contracts			$ 5,700