SHARE-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Weighted average grant date fair value
Liability for cash-settled restricted stock units	$ 19,060		$ 19,060		$ 20,648
Restricted Stock Units (RSUs)
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Line Items]
Share based compensation costs incurred	12,000	$ 15,000	41,000	$ 45,000
Tax benefit related to share-based compensation costs	2,000	$ 3,000	7,000	6,000
Fair value - vested during period			49,000	$ 47,000
Unrecognized compensation costs	90,000		$ 90,000		106,000
Unrecognized compensation costs - weighted average period expected to be recognized			2 years 6 months	2 years 7 months 6 days
Restricted Stock Units (RSUs) | Cash Settled
Weighted average grant date fair value
Liability for cash-settled restricted stock units	$ 19,000		$ 19,000		$ 19,000
Performance Vesting Restricted Stock Units | Share Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)			232
Granted (in shares)			127
Vested (in shares)			(61)
Forfeited (in shares)			(40)
Nonvested restricted stock units - end of period (in shares)	258		258
Weighted average grant date fair value
Nonvested restricted stock units - beginning of period (in usd per share)			$ 54.54
Granted (in usd per share)			54.70
Vested (in usd per share)			53.82
Forfeited (in usd per share)			64.01
Nonvested restricted stock units - end of period (in usd per share)	$ 53.31		$ 53.31
Performance Vesting Restricted Stock Units | Cash Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)			27
Granted (in shares)			0
Vested (in shares)			(12)
Forfeited (in shares)			(9)
Nonvested restricted stock units - end of period (in shares)	6		6
Service Based Restricted Stock Units | Share Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)			1,411
Granted (in shares)			522
Vested (in shares)			(465)
Forfeited (in shares)			(158)
Nonvested restricted stock units - end of period (in shares)	1,310		1,310
Weighted average grant date fair value
Nonvested restricted stock units - beginning of period (in usd per share)			$ 54.12
Granted (in usd per share)			54.88
Vested (in usd per share)			54.20
Forfeited (in usd per share)			54.54
Nonvested restricted stock units - end of period (in usd per share)	$ 54.34		$ 54.34
Service Based Restricted Stock Units | Cash Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)			932
Granted (in shares)			363
Vested (in shares)			(328)
Forfeited (in shares)			(94)
Nonvested restricted stock units - end of period (in shares)	873		873