UNAUDITED SUPPLEMENTARY DATA (Additional Information) (Details) - USD ($)	3 Months Ended												12 Months Ended
	Dec. 31, 2016	[1]	Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings (loss) from continuing operations	$ 108,063,000		$ 145,137,000	[1]	$ 127,241,000	[1]	$ 41,965,000	[1]	$ 93,560,000	$ 126,202,000	$ 49,819,000	$ (36,667,000)	$ 422,406,000	$ 232,914,000	$ 207,146,000
Net earnings (loss)	$ 112,600,000		$ 142,024,000	[1]	$ 124,709,000	[1]	$ 40,158,000	[1]	$ 88,888,000	$ 123,805,000	$ 48,162,000	$ (39,678,000)	$ 419,491,000	$ 221,177,000	$ 204,923,000
Net earnings per share, basic	$ 0.85		$ 1.07	[1]	$ 0.93	[1]	$ 0.30	[1]	$ 0.67	$ 0.93	$ 0.36	$ (0.30)	$ 3.15	$ 1.66	$ 1.56
Net earnings per share, diluted	$ 0.83		$ 1.05	[1]	$ 0.92	[1]	$ 0.30	[1]	$ 0.65	$ 0.91	$ 0.36	$ (0.30)	$ 3.09	$ 1.64	$ 1.54
Restatement Adjustment [Member]
Earnings (loss) from continuing operations			$ 2,259,000		$ 959,000		$ 21,234,000
Net earnings (loss)			$ 2,259,000		$ 959,000		$ 21,234,000
Net earnings per share							$ 0.16
Net earnings per share, basic			$ 0.02
Net earnings per share, diluted			$ 0.01		$ 0.01

[1] 1Amounts are revised to reflect the early adoption of ASU 2016-09 (See Note 1, caption Accounting Standards Recently Adopted) in the fourth quarter of 2016 and presented as adopted as of the beginning of the year. Earnings from continuing operations and Net earnings were increased, as follows: March 31 - $21,234,000 ($0.16 per share); June 30 - $959,000 ($0.01 in diluted net earnings per share only); and September 30 - $2,259,000 ($0.02 per share basic and $0.01 per share diluted).