SHARE-BASED COMPENSATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Abstract]
Liability for cash-settled restricted stock units	$ 12,946		$ 12,946		$ 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	13,000	$ 14,000	29,000	$ 29,000
Tax benefit related to share-based compensation costs	2,000	3,000	4,000	4,000
Fair value - vested during period			49,000	47,000
Unrecognized compensation costs	105,000	121,000	$ 105,000	$ 121,000
Unrecognized compensation costs - weighted average period expected to be recognized			2 years 8 months 12 days	2 years 9 months 18 days
Restricted Stock Units (RSUs) | Cash Settled
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Abstract]
Liability for cash-settled restricted stock units	$ 13,000	$ 13,000	$ 13,000	$ 13,000
Performance Vesting Restricted Stock Units | Share Settled
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Roll Forward]
Nonvested restricted stock units - beginning of period (in shares)			232
Granted (in shares)			127
Vested (in shares)			(61)
Forfeited (in shares)			0
Nonvested restricted stock units - end of period (in shares)	298		298
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Abstract]
Weighted average grant date fair value - beginning of period (in usd per share)			$ 54.54
Weighted average grant date fair value - granted (in usd per share)			54.70
Weighted average grant date fair value - vested (in usd per share)			53.82
Weighted average grant date fair value - forfeited (in usd per share)			0
Weighted average grant date fair value - end of period (in usd per share)	$ 54.76		$ 54.76
Performance Vesting Restricted Stock Units | Cash Settled
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Roll Forward]
Nonvested restricted stock units - beginning of period (in shares)			27
Granted (in shares)			0
Vested (in shares)			(12)
Forfeited (in shares)			0
Nonvested restricted stock units - end of period (in shares)	15		15
Service Based Restricted Stock Units | Share Settled
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Roll Forward]
Nonvested restricted stock units - beginning of period (in shares)			1,411
Granted (in shares)			512
Vested (in shares)			(463)
Forfeited (in shares)			(126)
Nonvested restricted stock units - end of period (in shares)	1,334		1,334
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Abstract]
Weighted average grant date fair value - beginning of period (in usd per share)			$ 54.12
Weighted average grant date fair value - granted (in usd per share)			54.70
Weighted average grant date fair value - vested (in usd per share)			54.20
Weighted average grant date fair value - forfeited (in usd per share)			54.57
Weighted average grant date fair value - end of period (in usd per share)	$ 54.27		$ 54.27
Service Based Restricted Stock Units | Cash Settled
Reconcilation of Beginning and Ending Balance of Nonvested Restricted Stock (including RSUs) [Roll Forward]
Nonvested restricted stock units - beginning of period (in shares)			932
Granted (in shares)			354
Vested (in shares)			(327)
Forfeited (in shares)			(62)
Nonvested restricted stock units - end of period (in shares)	897		897