Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning balance (in shares) at Feb. 28, 2018		26,576,000
Beginning balance at Feb. 28, 2018	$ 1,014,459	$ 2,658	$ 230,676	$ 631	$ 780,494
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Income from continuing operations	82,190				82,190
Loss from discontinued operations	(381)				(381)
Other comprehensive income (loss), net of tax	4,016			4,016
Exercise of stock options (in shares)		111,000
Exercise of stock options	5,515	$ 11	5,504
Net issuance and settlement of restricted stock (in shares)		140,000
Net issuance and settlement of restricted stock	0	$ 14	(14)
Issuance of common stock related to stock purchase plan (in shares)		17,000
Issuance of common stock related to stock purchase plan	$ 1,335	$ 2	1,333
Common stock repurchased and retired (in shares)	(57,072,000)	(464,000)
Common stock repurchased and retired	$ (42,240)	$ (46)	(6,877)		(35,317)
Share-based compensation	11,013		11,013
Ending balance (in shares) at Aug. 31, 2018		26,380,000
Ending balance at Aug. 31, 2018	1,075,740	$ 2,635	241,633	4,647	826,825
Beginning balance (in shares) at May. 31, 2018		26,317,000
Beginning balance at May. 31, 2018	1,023,697	$ 2,629	233,783	4,068	783,217
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Income from continuing operations	44,017				44,017
Loss from discontinued operations	0
Other comprehensive income (loss), net of tax	579			579
Exercise of stock options (in shares)		67,000
Exercise of stock options	3,459	$ 7	3,452
Net issuance and settlement of restricted stock (in shares)		3,000
Net issuance and settlement of restricted stock	0
Issuance of common stock related to stock purchase plan	$ 0
Common stock repurchased and retired (in shares)	(7,477,000)	(7,000)
Common stock repurchased and retired	$ (692)		(292)		(400)
Share-based compensation	4,689		4,689
Ending balance (in shares) at Aug. 31, 2018		26,380,000
Ending balance at Aug. 31, 2018	1,075,740	$ 2,635	241,633	4,647	826,825
Beginning balance (in shares) at Feb. 28, 2019		24,946,000
Beginning balance at Feb. 28, 2019	996,637	$ 2,495	246,585	1,191	746,366
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Income from continuing operations	86,789				86,789
Other comprehensive income (loss), net of tax	$ (5,946)			(5,946)
Exercise of stock options (in shares)	61,765	62,000
Exercise of stock options	$ 3,633	$ 6	3,627
Net issuance and settlement of restricted stock (in shares)		178,000
Net issuance and settlement of restricted stock	0	$ 18	(18)
Issuance of common stock related to stock purchase plan (in shares)		15,000
Issuance of common stock related to stock purchase plan	$ 1,408	$ 1	1,407
Common stock repurchased and retired (in shares)	(70,558,000)	(71,000)
Common stock repurchased and retired	$ (9,131)	$ (7)	(8,591)		(533)
Share-based compensation	13,985		13,985
Ending balance (in shares) at Aug. 31, 2019		25,130,000
Ending balance at Aug. 31, 2019	1,087,375	$ 2,513	256,995	(4,755)	832,622
Beginning balance (in shares) at May. 31, 2019		25,101,000
Beginning balance at May. 31, 2019	1,036,179	$ 2,510	249,079	(2,011)	786,601
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Income from continuing operations	46,095				46,095
Other comprehensive income (loss), net of tax	$ (2,744)			(2,744)
Exercise of stock options (in shares)	26,368	27,000
Exercise of stock options	$ 1,807	$ 2	1,805
Net issuance and settlement of restricted stock (in shares)		5,000
Net issuance and settlement of restricted stock	0	$ 1	(1)
Issuance of common stock related to stock purchase plan (in shares)		0
Issuance of common stock related to stock purchase plan	$ 0	$ 0	0
Common stock repurchased and retired (in shares)	(2,354,000)	(3,000)
Common stock repurchased and retired	$ (343)		(269)		(74)
Share-based compensation	6,381		6,381
Ending balance (in shares) at Aug. 31, 2019		25,130,000
Ending balance at Aug. 31, 2019	$ 1,087,375	$ 2,513	$ 256,995	$ (4,755)	$ 832,622