Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue	$ 1,909,482	$ 1,921,507	$ 2,271,603
Cost of services and products	1,780,256	1,726,897	1,992,376
Gross Margin	129,226	194,610	279,227
Selling, general and administrative expense	198,259	183,954	208,463
Goodwill, Impairment Loss	76,449	0	0
Income from Operations	(145,482)	10,656	70,764
Interest income	9,962	7,355	3,900
Interest expense, net of amounts capitalized	(37,742)	(27,817)	(25,318)
Equity earnings of unconsolidated affiliates	(3,783)	(1,983)	244
Other income (expense), net	(8,788)	(6,055)	(6,244)
Income before Income Taxes	(185,833)	(17,844)	43,346
Income Tax Expense (Benefit)	26,494	(184,242)	18,760
Net Income	$ (212,327)	$ 166,398	$ 24,586
Cash Dividends declared per Share	$ 0.00	$ 0.45	$ 0.96
Basic Earnings per Share	$ (2.16)	$ 1.69	$ 0.25
Weighted Average Number of Shares Outstanding, Basic	98,496	98,238	98,035
Diluted Earnings per Share	$ (2.16)	$ 1.68	$ 0.25
Weighted Average Number of Shares Outstanding, Diluted	98,496	98,764	98,424