FOREIGN OPERATIONS: (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Financial information by geographic area
Revenues	$ 277,131	$ 273,102	$ 277,467	$ 271,659	$ 287,255	$ 280,893	$ 286,432	$ 276,044	$ 1,099,359	$ 1,130,624	$ 1,113,755
Long-lived assets excluding financial instruments	726,610				760,772				726,610	760,772
Foreign
Financial information by geographic area
Revenues									144,892	160,663	162,113
Long-lived assets excluding financial instruments	72,060				82,728				72,060	82,728
Europe
Financial information by geographic area
Revenues									105,278	118,278	118,072
Long-lived assets excluding financial instruments	42,690				54,241				42,690	54,241
Asia/ Pacific
Financial information by geographic area
Revenues									34,876	36,158	32,282
Long-lived assets excluding financial instruments	28,139				26,900				28,139	26,900
Other
Financial information by geographic area
Revenues									4,738	6,227	11,759
Long-lived assets excluding financial instruments	1,231				1,587				1,231	1,587
United States
Financial information by geographic area
Revenues									954,467	969,961	951,642
Long-lived assets excluding financial instruments	$ 654,550				$ 678,044				$ 654,550	$ 678,044