EARNINGS PER SHARE - Reconciliation of weighted average shares outstanding (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
EARNINGS PER SHARE
Net (loss) income available for stockholders:	$ (35,173)	$ 64,885	$ (61,680)	$ 167,556
Less: Dividends paid		(22,939)	(33,599)	(68,822)
(Over distributed loss) Undistributed earnings	$ (35,173)	$ 41,946	$ (95,279)	$ 98,734
Basic shares outstanding:
Common stock	210,342	211,604	210,244	211,552
Restricted shares of common stock	3,337	3,598	3,373	3,648
Basic shares outstanding, Total	213,679	215,202	213,617	215,200
Diluted shares outstanding:
Common stock	210,342	211,604	210,244	211,552
Dilutive effect of stock based awards		1,132		1,116
Diluted shares outstanding excluding restricted shares of common stock, Total	210,342	212,736	210,244	212,668
Restricted shares of common stock	3,337	3,598	3,373	3,648
Diluted shares outstanding, Total	213,679	216,334	213,617	216,316