SHARE-BASED COMPENSATION (Share/Cash Settled Restricted Stock Units) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Weighted  average grant date fair value
Liability for cash-settled restricted stock units	$ 5,804		$ 13,273
Performance Vesting Restricted Stock Units | Share Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)	289
Granted (in shares)	122
Vested (in shares)	(66)
Forfeited (in shares)	(4)
Nonvested restricted stock units - end of period (in shares)	341
Weighted  average grant date fair value
Nonvested restricted stock units - beginning of period (in usd per share)	$ 55.92
Granted (in usd per share)	49.04
Vested (in usd per share)	48.89
Forfeited (in usd per share)	62.26
Nonvested restricted stock units - end of period (in usd per share)	$ 54.74
Service Based Restricted Stock Units | Share Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)	1,501
Granted (in shares)	1,192
Vested (in shares)	(546)
Forfeited (in shares)	(58)
Nonvested restricted stock units - end of period (in shares)	2,089
Weighted  average grant date fair value
Nonvested restricted stock units - beginning of period (in usd per share)	$ 56.50
Granted (in usd per share)	47.95
Vested (in usd per share)	56.45
Forfeited (in usd per share)	56.10
Nonvested restricted stock units - end of period (in usd per share)	$ 51.65
Service Based Restricted Stock Units | Cash Settled
Number of restricted stock units
Nonvested restricted stock units - beginning of period (in shares)	471
Granted (in shares)	0
Vested (in shares)	(223)
Forfeited (in shares)	(17)
Nonvested restricted stock units - end of period (in shares)	231
Restricted Stock Units (RSUs)
Weighted  average grant date fair value
Share-based compensation expense	$ 25,080	$ 25,410
Tax benefits associated with share-based compensation expense	4,075	3,995
Fair value of restricted stock units vested	41,671	46,490
Unrecognized share-based compensation expense	$ 107,267	$ 98,005
Expected weighted average period associated with the recognition of unrecognized share-based compensation expense	2 years 9 months 18 days	2 years 8 months 12 days
Restricted Stock Units (RSUs) | Cash Settled
Weighted  average grant date fair value
Liability for cash-settled restricted stock units	$ 5,804	$ 7,675