CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Total Shareholders' Equity	Noncontrolling Interests
BALANCE, beginning of year (in shares) at Dec. 31, 2017		139,918,000
Balance, beginning of year at Dec. 31, 2017	$ 3,492,399	$ 1,399	$ 88,222	$ (402,242)	$ 3,654,931	$ 3,342,310	$ 150,089
Increase (Decrease) in Shareholders' Equity
Net earnings (loss)	215,128				174,587	174,587	40,541
Other comprehensive loss	(81,219)			(79,936)		(79,936)	(1,283)
Dividends	(89,502)		(250)		(89,252)	(89,502)
Distributions to noncontrolling interests	(34,688)						(34,688)
Capital contributions by noncontrolling interests	4,293						4,293
Other noncontrolling interest transactions	2,852		3,936			3,936	(1,084)
Stock-based plan activity (in shares)		831,000
Stock-based plan activity	30,367	$ 8	30,359			30,367
BALANCE, end of year (in shares) at Sep. 30, 2018		140,749,000
Balance, end of year at Sep. 30, 2018	3,199,929	$ 1,407	122,267	(482,178)	3,401,528	3,043,024	156,905
BALANCE, beginning of year (in shares) at Jun. 30, 2018		140,700,000
Balance, beginning of year at Jun. 30, 2018	3,184,840	$ 1,406	111,368	(422,595)	3,353,176	3,043,355	141,485
Increase (Decrease) in Shareholders' Equity
Net earnings (loss)	96,025				77,345	77,345	18,680
Other comprehensive loss	(59,983)			(59,583)		(59,583)	(400)
Dividends	(29,121)		(128)		(28,993)	(29,121)
Distributions to noncontrolling interests	(2,436)						(2,436)
Capital contributions by noncontrolling interests	533						533
Other noncontrolling interest transactions	417		1,374			1,374	(957)
Stock-based plan activity (in shares)		49,000
Stock-based plan activity	9,654	$ 1	9,653			9,654
BALANCE, end of year (in shares) at Sep. 30, 2018		140,749,000
Balance, end of year at Sep. 30, 2018	3,199,929	$ 1,407	122,267	(482,178)	3,401,528	3,043,024	156,905
BALANCE, beginning of year (in shares) at Dec. 31, 2018		139,654,000
Balance, beginning of year at Dec. 31, 2018	3,118,050	$ 1,396	82,106	(542,478)	3,422,157	2,963,181	154,869
Increase (Decrease) in Shareholders' Equity
Net earnings (loss)	(1,366,333)				(1,355,218)	(1,355,218)	(11,115)
Other comprehensive loss	(10,968)			(9,425)		(9,425)	(1,543)
Dividends	(89,123)		218		(89,341)	(89,123)
Distributions to noncontrolling interests	(26,123)						(26,123)
Capital contributions by noncontrolling interests	10,581						10,581
Other noncontrolling interest transactions	1,954		4,188			4,188	(2,234)
Stock-based plan activity (in shares)		520,000
Stock-based plan activity	25,348	$ 3	25,345			25,348
BALANCE, end of year (in shares) at Sep. 30, 2019		140,174,000
Balance, end of year at Sep. 30, 2019	1,683,930	$ 1,399	111,857	(551,903)	1,998,142	1,559,495	124,435
BALANCE, beginning of year (in shares) at Jun. 30, 2019		140,174,000
Balance, beginning of year at Jun. 30, 2019	2,497,489	$ 1,399	113,042	(510,008)	2,769,804	2,374,237	123,252
Increase (Decrease) in Shareholders' Equity
Net earnings (loss)	(729,539)				(741,984)	(741,984)	12,445
Other comprehensive loss	(43,644)			(41,895)		(41,895)	(1,749)
Dividends	(29,678)		0		(29,678)	(29,678)
Distributions to noncontrolling interests	(10,551)						(10,551)
Capital contributions by noncontrolling interests	2,760						2,760
Other noncontrolling interest transactions	(617)		1,105			1,105	(1,722)
Stock-based plan activity (in shares)		0
Stock-based plan activity	(2,290)	$ 0	(2,290)			(2,290)
BALANCE, end of year (in shares) at Sep. 30, 2019		140,174,000
Balance, end of year at Sep. 30, 2019	$ 1,683,930	$ 1,399	$ 111,857	$ (551,903)	$ 1,998,142	$ 1,559,495	$ 124,435