CAPITAL STOCK AND STOCK AWARD PLANS - Summary of Stock Options Grants by First Vesting Date (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	4,122,292
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 13.20
Unvested Options (in shares)	3,305,483
December 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	1,423,053
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 12.66
Unvested Options (in shares)	855,984
December 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	1,253,169
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 12.60
Unvested Options (in shares)	1,003,429
December 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	1,446,070
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 14.24
Unvested Options (in shares)	1,446,070
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	2,683,996
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 12.94
Unvested Options (in shares)	1,086,075
Performance Shares | December 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	1,412,773
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 11.83
Unvested Options (in shares)	403,149
Performance Shares | December 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted, Net of Forfeitures (in shares)	1,271,223
Weighted Average Grant Date Fair Value (in dollars per share) | $ / shares	$ 14.17
Unvested Options (in shares)	682,926