Revenue Recognition (Contract Liabilities) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Assets, Beginning balance	$ 277,734
Contract Liabilities, Current, Beginning balance	194,227
Revenue recognized that was included in contract liabilities at the beginning of the period	(17,026)	$ (4,412)
Amounts transferred from contract assets to receivables	12,232	(44,276)
Contract Assets, Ending balance	262,231	309,196
Contract Liabilities, Current, Ending balance	209,092	219,633
Short-term Contract with Customer
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Assets, Beginning balance	277,734	272,914
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	321,040	386,250
Billings arising during the period in excess of revenue recognized	0	0
Amounts transferred from contract assets to receivables	(326,634)	(335,505)
Other contract asset, net	(9,909)	(14,463)
Long-term Contract with Customer
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Assets, Beginning balance	1,139	9,280
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	54	511
Billings arising during the period in excess of revenue recognized	0	0
Amounts transferred from contract assets to receivables	(28)	(93)
Other contract asset, net	(86)	(6,689)
Contract Assets, Ending balance	1,079	3,009
Short-term Contract with Customer, Liability
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Liabilities, Current, Beginning balance	194,227	221,095
Revenue recognized that was included in contract liabilities at the beginning of the period	(112,835)	(138,994)
Revenue recognized in the period in excess of billings	0	0
Billings arising during the period in excess of revenue recognized	126,591	141,156
Amounts transferred from contract assets to receivables	0	0
Other contract liability, net	1,109	(3,624)
Long-term Contract With Customer, Liability
Change In Contract With Customer, Asset And Liability [Roll Forward]
Contract Liabilities, Noncurrent, Beginning balance	822	1,652
Revenue recognized that was included in contract liabilities at the beginning of the period	0	(646)
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	(19)	(31)
Contract Liabilities, Noncurrent, Ending balance	$ 803	$ 975