STOCK-BASED COMPENSATION (Summary Of Stock Option Activity) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of year (in shares) | shares	2,083
Granted (in shares) | shares	187
Exercised (in shares) | shares	(531)
Forfeited or Expired (in shares) | shares	0
Outstanding at end of year (in shares) | shares	1,739
Vested or expected to vest at end of year (in shares) | shares	1,739
Exercisable at end of year (in shares) | shares	1,333
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Outstanding at beginning of year (in dollars per share) | $ / shares	$ 20.65
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	41.72
Weighted Average Exercise Price, Exercised (in dollars per share) | $ / shares	17.60
Weighted Average Exercise Price, Forfeited or Expired (in dollars per share) | $ / shares	0.00
Weighted Average Exercise Price, Outstanding at end of year (in dollars per share) | $ / shares	23.84
Weighted Average Exercise Price, Vested or expected to vest at end of year (in dollars per share) | $ / shares	23.84
Weighted Average Exercise Price, Exercisable at end of year (in dollars per share) | $ / shares	$ 19.95
Weighted Average Contractual Term in Years, Outstanding at end of year	3 years 6 months 14 days
Weighted Average Contractual Term in Years, Vested or expected to vest at end of year	3 years 6 months 14 days
Weighted Average Contractual Term in Years, Exercisable at end of year	2 years 7 months 16 days
Aggregate Intrinsic Value, Outstanding at end of year | $	$ 41,753
Aggregate Intrinsic Value, Vested or expected to vest at end of year | $	41,753
Aggregate Intrinsic Value, Exercisable at end of year | $	$ 37,208