CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balances at Feb. 28, 2018	$ 198,916	$ 357	$ 218,217	$ (19,459)	$ (199)
Balances (in shares) at Feb. 28, 2018		35,718
Cumulative adjustment upon adoption, net of tax | ASU 2016-01 [Member]				434	(434)
Cumulative adjustment upon adoption, net of tax | ASC 606 [Member]	(1,595)			(1,595)
Net income (loss)	8,511			8,511
Stock-based compensation expense	2,467		2,467
Shares issued on net share settlement of equity awards	(233)		(233)
Shares issued on net share settlement of equity awards (in shares)		21
Exercise of stock options	68		68
Exercise of stock options (in shares)		38
Repurchases of common stock	(5,710)	$ (2)	(5,708)
Repurchases of common stock (in shares)		(270)
Other comprehensive income, net of tax	17				17
Balances at May. 31, 2018	202,441	$ 355	214,811	(12,109)	(616)
Balances (in shares) at May. 31, 2018		35,507
Balances at Feb. 28, 2018	198,916	$ 357	218,217	(19,459)	(199)
Balances (in shares) at Feb. 28, 2018		35,718
Net income (loss)	7,657
Balances at Aug. 31, 2018	209,736	$ 348	222,981	(12,963)	(630)
Balances (in shares) at Aug. 31, 2018		34,758
Balances at May. 31, 2018	202,441	$ 355	214,811	(12,109)	(616)
Balances (in shares) at May. 31, 2018		35,507
Net income (loss)	(854)			(854)
Equity component of 2025 Convertible Notes, net of tax	51,902		51,902
Purchase of capped call of 2025 Convertible Notes, net of tax	(15,870)		(15,870)
Debt issuance costs of 2025 Convertible Notes allocated to equity, net of tax	(1,649)		(1,649)
Equity component of the repurchased 2020 Convertible Notes	(6,088)		(6,088)
Unwind of note hedges and warrants of 2020 Convertible Notes	3,122		3,122
Stock-based compensation expense	2,680		2,680
Shares issued on net share settlement of equity awards	(3,113)	$ 2	(3,115)
Shares issued on net share settlement of equity awards (in shares)		135
Issuance of shares for restricted stock awards		$ 1	(1)
Issuance of shares for restricted stock awards (in shares)		84
Exercise of stock options	33	$ 1	32
Exercise of stock options (in shares)		17
Repurchases of common stock	(22,854)	$ (11)	(22,843)
Repurchases of common stock (in shares)		(985)
Other comprehensive income, net of tax	(14)				(14)
Balances at Aug. 31, 2018	209,736	$ 348	222,981	(12,963)	(630)
Balances (in shares) at Aug. 31, 2018		34,758
Balances at Feb. 28, 2019	205,653	$ 336	208,205	(2,227)	(661)
Balances (in shares) at Feb. 28, 2019		33,555
Net income (loss)	(8,693)			(8,693)
Stock-based compensation expense	2,543		2,543
Shares issued on net share settlement of equity awards	(219)		(219)
Shares issued on net share settlement of equity awards (in shares)		13
Exercise of stock options	97		97
Exercise of stock options (in shares)		39
Other comprehensive income, net of tax	(269)				(269)
Balances at May. 31, 2019	199,112	$ 336	210,626	(10,920)	(930)
Balances (in shares) at May. 31, 2019		33,607
Balances at Feb. 28, 2019	205,653	$ 336	208,205	(2,227)	(661)
Balances (in shares) at Feb. 28, 2019		33,555
Net income (loss)	$ (16,062)
Exercise of stock options (in shares)	83
Balances at Aug. 31, 2019	$ 193,296	$ 341	213,192	(18,289)	(1,948)
Balances (in shares) at Aug. 31, 2019		34,113
Balances at May. 31, 2019	199,112	$ 336	210,626	(10,920)	(930)
Balances (in shares) at May. 31, 2019		33,607
Net income (loss)	(7,369)			(7,369)
Stock-based compensation expense	3,183		3,183
Shares issued on net share settlement of equity awards	(1,510)	$ 2	(1,512)
Shares issued on net share settlement of equity awards (in shares)		181
Issuance of shares for restricted stock awards		$ 2	(2)
Issuance of shares for restricted stock awards (in shares)		197
Exercise of stock options and contributions to ESPP	898	$ 1	897
Exercise of stock options and contributions to ESPP (in shares)		128
Other comprehensive income, net of tax	(1,018)				(1,018)
Balances at Aug. 31, 2019	$ 193,296	$ 341	$ 213,192	$ (18,289)	$ (1,948)
Balances (in shares) at Aug. 31, 2019		34,113