Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue	$ 1,869,275	$ 1,827,889	$ 2,048,124
Cost of services and products	1,605,210	1,663,948	1,949,880
Other Asset Impairment Charges	0	70,445	159,353
Gross Margin	264,065	163,941	98,244
Selling, general and administrative expense	224,266	195,695	214,891
Goodwill, Impairment Loss	0	343,880	14,713
Income from Operations	39,799	(446,079)	(290,713)
Interest income	2,477	3,083	7,893
Interest expense, net of amounts capitalized	(38,810)	(43,900)	(42,711)
Equity earnings of unconsolidated affiliates	594	2,268	1,331
Other Nonoperating Income	(9,769)	(14,269)	(6,621)
Income before Income Taxes	(5,709)	(498,897)	(330,821)
Income Tax Expense (Benefit)	43,598	(2,146)	17,623
Net Income	$ (49,307)	$ (496,751)	$ (348,444)
Basic Earnings per Share	$ (0.49)	$ (5.01)	$ (3.52)
Weighted Average Number of Shares Outstanding, Basic	99,706	99,233	98,876
Diluted Earnings per Share	$ (0.49)	$ (5.01)	$ (3.52)
Weighted Average Number of Shares Outstanding, Diluted	99,706	99,233	98,876