EQUITY - NARRATIVE (Details) - USD ($)				1 Months Ended		9 Months Ended		12 Months Ended	79 Months Ended
	Aug. 15, 2017	May 15, 2017	Feb. 15, 2017	May 31, 2017	May 31, 2014	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Sep. 30, 2017	Mar. 31, 2011
Class of Stock [Line Items]
Payment of dividends, preferred stock and Preference Stock						$ 72,468,000	$ 80,344,000
Proceeds from stock options and ESPP						$ 105,717,000	$ 76,601,000
Stock repurchase program, authorized amount										$ 1,500,000,000.0
Stock repurchased (in shares)						5,456,538			11,713,442
Stock repurchased						$ 676,900,000
Accrued treasury stock purchases						7,180,000		$ 0	$ 7,180,000
Accrued dividend RSU						8,000,000			$ 8,000,000
Dividends Declared and Paid
Class of Stock [Line Items]
Paid dividend RSU						2,900,000
Accounts Payable and Accrued Liabilities
Class of Stock [Line Items]
Stock repurchased						$ 1,100,000,000
Preferred Stock - Series B
Class of Stock [Line Items]
Depository shares, percentage of preferred shares (in shares)						0.1			0.1
Convertible Preferred Stock Subject to Mandatory Redemption
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)						$ 0.01		$ 0.01	$ 0.01
Convertible Preferred Stock Subject to Mandatory Redemption | Preferred Stock - Series A
Class of Stock [Line Items]
Preferred stock, dividend rate percentage (in percent)						5.25%		5.25%
Preferred stock, conversion rate						93.37%
Payment of dividends, preferred stock and Preference Stock		$ 7,900,000	$ 7,900,000
Convertible Preferred Stock Subject to Mandatory Redemption | Preferred Stock - Series A | Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)					6,000,000
Preferred stock, dividend rate percentage (in percent)					5.25%
Preferred stock, par value (in dollars per share)					$ 0.01
Number of shares converted						5,602,153			5,602,153
Convertible Preferred Stock Subject to Mandatory Redemption | Preferred Stock - Series B
Class of Stock [Line Items]
Preferred stock, dividend rate percentage (in percent)						5.50%		5.50%
Payment of dividends, preferred stock and Preference Stock	$ 18,900,000	$ 18,900,000	$ 18,900,000
Preferred stock, liquidation preference per share (in dollars per share)						$ 1,000.00			$ 1,000.00
Shares issued, price per share (in dollars per share)						$ 100.00			100.00
Convertible Preferred Stock Subject to Mandatory Redemption | Preferred Stock - Series B | Minimum
Class of Stock [Line Items]
Conversion factor, preferred stock (in shares)						8.6870
Convertible Preferred Stock Subject to Mandatory Redemption | Preferred Stock - Series B | Maximum
Class of Stock [Line Items]
Conversion factor, preferred stock (in shares)						10.4244
Convertible Preferred Stock Subject to Mandatory Redemption | Preferred Stock - Series B | Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate percentage (in percent)						5.50%
Preferred stock, par value (in dollars per share)						$ 0.01			$ 0.01
Preferred stock, conversion rate				86.87%
Depository shares, amount issued (in shares)				140		13,749,860			13,749,860