STOCK BASED COMPENSATION: (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Restricted Stock Units, Vested and Expected to Vest

			2017			2016
	Number		Weighted Average Grant Date	Number		Weighted Average Grant Date
(shares in thousands)	Outstanding		Fair Value	Outstanding		Fair Value
Nonvested balance at January 1,	20,524		32.83	20,466		33.26
Granted during the year	16,562		46.70	20,943		32.35
Vested during the year	(19,067	)	37.03	(20,885	)	32.76
Forfeited during the year	—		—	—		—
Nonvested balance at December 31,	18,019		41.14	20,524		32.83