Consolidated Statement of Stockholders Equity (USD $) In Thousands	Total USD ($)	Common Stock	Additional Paid-in Capital USD ($)	Retained Earnings USD ($)	Accumulated Other Comprehensive Income (Loss) USD ($)	Noncontrolling Interest USD ($)	Stockholders' Equity, Total USD ($)	Non Controlling Interest With Redemption Feature USD ($)
Noncontrolling interest with redemption feature at Jan. 31, 2012								$ 9,266
Stockholders' equity at Jan. 31, 2012			775,362	62,032	28,680	0	866,074
Common stock, shares outstanding at Jan. 31, 2012		109,346
Net income (loss), including portion attributable to nonredeemable noncontrolling interest				138,736			138,736
Net income (loss) attributable to noncontrolling interest	(102)							(102)
Other comprehensive income (loss)	(3,337)				(3,281)		(3,281)
Other comprehensive income (loss) attributable to noncontrolling Interest								(56)
Adjustment of noncontrolling interest to redemption value				(3,590)			(3,590)	3,590
Stock issued under stock awards and stock purchase plans, amount			46,756				46,756
Stock issued under stock awards and stock purchase plans, shares		5,875
Stock repurchased, amount			(33,914)				(33,914)
Stock repurchased, shares		(2,245)
Stock compensation expense			23,697				23,697
Stock withheld for taxes, amount			(1,265)				(1,265)
Stock withheld for taxes, shares		(74)
Tax benefit associated with the exercise of stock options			266				266
Noncontrolling interest with redemption feature at Jan. 31, 2013								12,698
Stockholders' equity at Jan. 31, 2013			810,902	197,178	25,399	0	1,033,479
Common stock, shares outstanding at Jan. 31, 2013		112,902
Net income (loss), including portion attributable to nonredeemable noncontrolling interest				155,258			155,258
Net income (loss) attributable to noncontrolling interest	(1,700)							(1,700)
Other comprehensive income (loss)	(6,601)				(6,596)		(6,596)
Other comprehensive income (loss) attributable to noncontrolling Interest								(5)
Adjustment of noncontrolling interest to redemption value				(4,486)			(4,486)	4,486
Dividends				(20,398)			(20,398)
Stock issued under stock awards and stock purchase plans, amount			53,013				53,013
Stock issued under stock awards and stock purchase plans, shares		5,618
Stock repurchased, amount			(49,995)				(49,995)
Stock repurchased, shares		(2,593)
Stock compensation expense			29,350				29,350
Stock withheld for taxes, amount			(4,717)				(4,717)
Stock withheld for taxes, shares		(205)
Tax benefit associated with the exercise of stock options			386				386
Noncontrolling interest with redemption feature at Jan. 31, 2014	15,479							15,479
Stockholders' equity at Jan. 31, 2014	1,185,294		838,939	327,552	18,803	0	1,185,294
Common stock, shares outstanding at Jan. 31, 2014	115,722	115,722
Net income (loss), including portion attributable to nonredeemable noncontrolling interest				147,139		29	147,168
Net income (loss) attributable to noncontrolling interest	(1,962)							(1,991)
Other comprehensive income (loss)	(30,645)				(30,690)	(1)	(30,691)
Other comprehensive income (loss) attributable to noncontrolling Interest								46
Recognition of noncontrolling interest						200	200
Adjustment of noncontrolling interest to redemption value				121			121	(121)
Dividends				(22,911)			(22,911)
Stock issued under stock awards and stock purchase plans, amount			29,990				29,990	331
Stock issued under stock awards and stock purchase plans, shares		3,349
Stock repurchased, amount			(70,053)				(70,053)	(372)
Stock repurchased, shares		(3,174)
Stock compensation expense			35,807				35,807
Stock withheld for taxes, amount			(2,351)				(2,351)
Stock withheld for taxes, shares		(107)
Tax benefit associated with the exercise of stock options			280				280
Noncontrolling interest with redemption feature at Jan. 31, 2015	13,372							13,372
Stockholders' equity at Jan. 31, 2015	$ 1,272,854		$ 832,612	$ 451,901	$ (11,887)	$ 228	$ 1,272,854
Common stock, shares outstanding at Jan. 31, 2015	115,790	115,790