COMMITMENTS, CONTINGENCIES AND OFF-BALANCE ARRANGEMENTS - LEASE LITIGATION EMPLOYMENT (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) item	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Operating Leases Future Minimum Payments Due Future Minimum Sublease Rentals	$ 170.2
Total	170.2
Rent expense	$ 32.0	$ 32.4	$ 29.7
Executive Officer One
Commitments and Contingencies Disclosure [Line Items]
Terms of employment and compensation agreement with a key officer	An agreement for one of the officers provides for the officer to earn a minimum of $0.9 per year, which may be adjusted annually as determined by the Company's Board of Directors or the Compensation Committee of the Board of Directors, for a three-year period from the effective date (as defined in such agreement), which is automatically extended for successive one-year period(s) thereafter, unless either party provides notice of non-renewal, as well as quarterly contributions to a tax-deferred compensation plan which in the aggregate, on an annual basis, would amount to a contribution equal to 100% of such officer's base salary in effect at the time.
Retirement compensation payment factor of base salary | item	100
Executive Officer One | Minimum
Commitments and Contingencies Disclosure [Line Items]
Annual earning of a key officer	$ 0.9
Executive Officer Two
Commitments and Contingencies Disclosure [Line Items]
Terms of employment and compensation agreement with a key officer	One other agreement provides for an officer to receive annual minimum compensation of $1.0 per year, which may be adjusted annually as determined by the Company's Compensation Committee of the Board of Directors, for a three-year period ending from any date after which it is measured, and to receive monthly contributions to a tax-deferred compensation plan in an amount equal to 7.5% of the monthly amount of such officer's base salary in effect at the time and, on January 1 of each year, a contribution to such plan in an amount equal to 20% of such officer's base salary in effect at the time.
Retirement compensation payment factor of base salary | item	20
Retirement compensation payment, percentage of the three years' annual salary	7.50%
Executive Officer Two | Minimum
Commitments and Contingencies Disclosure [Line Items]
Annual earning of a key officer	$ 1.0
Real Estate
Commitments and Contingencies Disclosure [Line Items]
Operating Leases Future Minimum Payments Due Future Minimum Sublease Rentals	$ 143.8