Other Comprehensive Income (Loss) - Significant Items Reclassified Out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassifications out of accumulated other comprehensive income (loss)
Total cost of revenue	$ (3,869,606)	$ (3,654,953)	$ (11,177,807)	$ (10,959,757)
Income tax expense	(490,077)	(28,710)	(368,289)	(39,260)
Net of tax	0	0	0	709
Interest expense	(18,984)	(24,238)	(56,490)	(58,131)
NET EARNINGS (LOSS)	(729,539)	96,025	(1,366,333)	215,128
Corporate general and administrative expense	(10,362)	(61,058)	(115,426)	(134,726)
Ownership Share of Equity Method Investees’ Other Comprehensive Income (Loss) | Reclassified out of AOCI
Reclassifications out of accumulated other comprehensive income (loss)
Total cost of revenue	(192)	(200)	(569)	(1,099)
Income tax expense	48	49	142	291
Net of tax	(144)	(151)	(427)	(808)
Defined Benefit Pension and Postretirement Plans | Reclassified out of AOCI
Reclassifications out of accumulated other comprehensive income (loss)
Income tax expense	136	3,674	425	4,687
Corporate general and administrative expense	(2,126)	(20,062)	(6,518)	(24,945)
Net of tax	(1,990)	(16,388)	(6,093)	(20,258)
Unrealized Gain (Loss) on Available-for- Sale Securities | Reclassified out of AOCI
Reclassifications out of accumulated other comprehensive income (loss)
Income tax expense	0	0	0	425
NET EARNINGS (LOSS)	0	0	0	(709)
Corporate general and administrative expense	0	0	0	(1,134)
Unrealized Gain (Loss) on Derivative Contracts | Reclassified out of AOCI
Reclassifications out of accumulated other comprehensive income (loss)
Income tax expense	365	892	1,296	1,542
NET EARNINGS (LOSS)	(550)	(1,784)	(1,920)	(3,091)
Unrealized Gain (Loss) on Derivative Contracts | Reclassified out of AOCI | Foreign currency contracts
Reclassifications out of accumulated other comprehensive income (loss)
Total cost of revenue	(496)	(2,257)	(1,958)	(3,375)
Unrealized Gain (Loss) on Derivative Contracts | Reclassified out of AOCI | Interest rate contracts
Reclassifications out of accumulated other comprehensive income (loss)
Interest expense	$ (419)	$ (419)	$ (1,258)	$ (1,258)