EARNINGS (LOSS) PER SHARE AND STOCKHOLDERS' EQUITY: Narrative (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Antidilutive securities excluded from computation of earnings per share, amount	1,308	39	324	263
Repurchase of stock (in shares)	900		900
Payments for repurchase of common stock			$ 19,776	$ 30,542
Treasury stock, at cost	$ 1,067,090		1,067,090		$ 1,039,345
Accumulated other comprehensive income	$ 9,410		$ 9,410		$ 7,999
Stock Options And Warrants And Restricted Stock Units
Antidilutive securities excluded from computation of earnings per share, amount	2,200		2,500
Common Stock Repurchase Program
Stock repurchase program, authorized amount	$ 400,000		$ 400,000
Repurchase of stock (in shares)	17,700		17,700
Treasury stock, at cost	$ 305,500		$ 305,500
Stock repurchase program, remaining amount	$ 94,500		$ 94,500