EARNINGS PER SHARE: (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income (Numerator)
Income from continuing operations	$ 97,089	$ 48,768	$ 41,601	$ 27,657	$ 4,237	$ 30,551	$ 12,956	$ 16,515	$ 215,115	$ 64,259	$ 144,488
Net income loss attributable to noncontrolling interests included in continuing operations									(2,836)	(2,349)	(287)
Numerator for diluted earnings per common share from continuing operations available to common shareholders									212,279	61,910	144,381
Income from discontinued operations, net of taxes						6,100	5,103	355		11,558	465
Numerator for diluted earnings available to common shareholders									212,279	73,468	144,846
Shares (Denominator)
Weighted average common shares outstanding									97,114,000	93,207,000	81,020,000
Dilutive effect of stock settled appreciation rights, restricted stock awards and outstanding stock options (in shares)									705,000	638,000	36,000
Weighted-average common and common equivalent shares outstanding									97,819,000	93,845,000	81,310,000
Additional Disclosures
Antidilutive dilutive securities excluded from calculation of diluted earnings per share (in shares)									300,000	0	1,500,000
4.875% Notes
Earning Per Share
Interest rate (as a percent)	4.875%				4.875%	4.875%			4.875%	4.875%
Income (Numerator)
Income impact of assumed conversion of the 4.875% Notes, net of taxes											$ 180
Shares (Denominator)
Dilutive effect of 4.875% Notes											254,000