EARNINGS PER SHARE AND STOCKHOLDERS' EQUITY: Narrative (Details) - USD ($) shares in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018
Antidilutive securities excluded from computation of earnings per share, amount	119	20
Repurchase of stock (in shares)	1,900
Acquisition of treasury stock	$ 45,766,000	$ 0
Treasury stock, at cost	1,195,101,000		$ 1,139,291,000
Accumulated other comprehensive income	$ 8,899,000		$ 10,767,000
Stock Options And Warrants And Restricted Stock Units
Antidilutive securities excluded from computation of earnings per share, amount	2,400	2,800
Common Stock Repurchase Program
Stock repurchase program, authorized amount	$ 500,000,000
Repurchase of stock (in shares)	22,000
Treasury stock, at cost	$ 420,400,000
Stock repurchase program, remaining amount	$ 79,600,000