EMPLOYEE BENEFIT PLANS - Stock Options (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Stock option activity
Stock-Based Compensation Expense	$ 14,000,000	$ 18,000,000
Stock Options
Stock option activity
Outstanding at the beginning of the period (in shares)	1,606,842
Granted (in shares)		0
Exercised (in shares)	(3,950)	(77,658)
Forfeited/Expired (in shares)	(29,392)
Outstanding at the end of the period (in shares)	1,573,500		1,606,842
Vested and expected to vest at the end of the period (in shares)	1,573,500
Exercisable at the end of the period (in shares)	1,573,500
Weighted Average Exercise Price Per Share
Outstanding at the beginning of the period (in dollars per share)	$ 22.87
Exercised (in dollars per share)	4.56
Forfeited/Expired (in dollars per share)	4.56
Outstanding at the end of the period (in dollars per share)	22.75		$ 22.87
Vested and expected to vest at the end of the period (in dollars per share)	22.75
Exercisable at the end of the period (in dollars per share)	$ 22.75
Aggregate Intrinsic Value
Outstanding at the end of the period	$ 13,000,000
Vested and expected to vest at the end of the period	13,000,000
Exercisable at the end of the period	$ 13,000,000
Weighted Average Remaining Life
Outstanding at the end of the period	2 years 10 months 24 days		3 years 10 months 24 days
Vested and expected to vest at the end of the period	3 years 10 months 24 days
Exercisable at the end of the period	3 years 8 months 12 days
Other Disclosures
Aggregate Intrinsic value of awards exercised	$ 1,000,000	$ 1,000,000
Unrecognized compensation costs		$ 0