EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income (loss)	$ 71,480	$ 60,824
Denominator (shares in 000's):
Basic weighted average shares outstanding (in shares)	63,160,000	65,579,000
Effect of dilutive securities - Stock options and awards (in shares)	739,000	864,000
Diluted weighted average shares outstanding (in shares)	63,899,000	66,443,000
Earnings (loss) per share
Basic earnings (loss) per share (in dollars per share)	$ 1.13	$ 0.93
Diluted earnings (loss) per share (in dollars per share)	$ 1.12	$ 0.92
Anti-dilutive shares excluded from the computation of diluted earnings per share	498,694	174,325

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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