NOTES PAYABLE - DIRECT CORPORATE OBLIGATIONS (PREVIOUS SENIOR SECURED CREDIT AGREEMENT) (NARRATIVE) (Details) - USD ($)			12 Months Ended
	May 19, 2015	Sep. 28, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016
Debt Instrument [Line Items]
Amount outstanding prior to repayment					$ 925,000,000
Line of Credit [Member] | Secured Debt [Member] | Term Loan Facility, Six-Year [Member]
Debt Instrument [Line Items]
Debt instrument, term		6 years
Amount outstanding prior to repayment				$ 389,800,000
Line of Credit [Member] | Secured Debt [Member] | Term Loan Facility, Four-Year [Member]
Debt Instrument [Line Items]
Debt instrument, term		4 years
Amount outstanding prior to repayment				112,500,000
Line of Credit [Member] | Secured Debt [Member] | Senior Secured Credit Agreement [Member]
Debt Instrument [Line Items]
Additional debt payment			$ 19,800,000	$ 59,400,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, term	4 years
Maximum borrowing capacity	$ 150,000,000
Line of Credit [Member] | Revolving Credit Facility [Member] | Revolving Credit Facility, Three Year [Member]
Debt Instrument [Line Items]
Debt instrument, term		3 years
Maximum borrowing capacity		$ 50,000,000