BORROWINGS (Details 4) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jan. 18, 2013 7.5% Convertible Senior Notes	Dec. 31, 2013 7.5% Convertible Senior Notes	Dec. 31, 2012 7.5% Convertible Senior Notes	Dec. 31, 2011 7.5% Convertible Senior Notes	Jul. 13, 2012 7.0% convertible senior notes	Mar. 31, 2012 7.0% convertible senior notes	Dec. 31, 2011 7.0% convertible senior notes
Details of Company's borrowings
Interest rate (as a percent)					7.50%				7.00%
Convertible senior notes issued, principal amount			$ 166,028,000		$ 172,500,000		$ 166,028,000
Conversion rate of common stock shares per $1,000 principal amount (in shares per USD)					0.1418256
Principal amount used for debt instrument conversion ratio					1,000
Conversion rate of additional common shares issued upon conversion per $1,000 principal amount to account for the make-whole premium (in shares per USD)					0.0092324
Amount of debt that had been tendered for conversion	172,500,000	186,254,000			172,500,000
Number of common shares of the entity issued in exchange of convertible notes (in shares)	26.1				26.1
Carrying amount of equity component included in paid-in-capital							10,000,000
Total borrowings		6,020,465,000	6,338,407,000				166,000,000
Convertible debt principal amount							172,500,000
Debt discount, unamortized							6,500,000
Debt discount, amortized						0	1,300,000	1,200,000
Effective interest rate to amortize debt discount (as a percent)						8.60%
Interest expense, recognized						500,000	12,900,000	12,900,000
Principal amount of debt extinguishment									112,000,000	23,100,000	45,500,000
Loss on repurchase of convertible notes										400,000	1,700,000
Write-off of unamortized debt issuance costs		$ 6,674,000	$ 4,224,000	$ 2,194,000						$ 200,000	$ 100,000