Revenue Recognition (Contract Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Assets, Beginning balance	$ 272,914
Contract Liabilities, Current, Beginning balance	216,541
Revenue recognized that was included in contract liabilities at the beginning of the period	(15,705)	$ (5,567)
Amounts transferred from contract assets to receivables	(14,462)	1,631
Contract Assets, Ending balance	275,927	224,850
Contract Liabilities, Current, Ending balance	223,632	207,742
Short-term Contract with Customer
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Assets, Beginning balance	272,914	228,579
Revenue recognized that was included in contract liabilities at the beginning of the period	0	0
Revenue recognized in the period in excess of billings	203,856	155,444
Billings arising during the period in excess of revenue recognized	0	0
Amounts transferred from contract assets to receivables	(185,456)	(154,817)
Other contract asset, net	(15,387)	(4,356)
Long-term Contract with Customer
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Assets, Beginning balance	9,280	10,967
Revenue recognized that was included in contract liabilities at the beginning of the period	0	0
Revenue recognized in the period in excess of billings	504	0
Billings arising during the period in excess of revenue recognized	0	0
Amounts transferred from contract assets to receivables	(93)	(2,202)
Other contract asset, net	(7,229)	(19)
Contract Assets, Ending balance	2,462	8,746
Short-term Contract with Customer, Liability
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Liabilities, Current, Beginning balance	216,541	202,458
Revenue recognized that was included in contract liabilities at the beginning of the period	(85,636)	(73,417)
Revenue recognized in the period in excess of billings	0	0
Billings arising during the period in excess of revenue recognized	100,121	78,078
Amounts transferred from contract assets to receivables	0	0
Other contract liability, net	(7,394)	623
Long-term Contract With Customer, Liability
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Liabilities, Noncurrent, Beginning balance	1,652	1,370
Revenue recognized that was included in contract liabilities at the beginning of the period	(634)	0
Revenue recognized in the period in excess of billings	0	0
Billings arising during the period in excess of revenue recognized	0	0
Amounts transferred from contract assets to receivables	0	0
Other contract liability, net	(53)	(12)
Contract Liabilities, Noncurrent, Ending balance	$ 965	$ 1,358