Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Operating activities:
Net loss applicable to common stockholders	$ (15,941)	$ (25,339)	$ (34,421)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense	14,139	14,062	12,453
Loss on disposal of discontinued operations, net of tax	0	0	1,537
Loss on sub-lease	501	546	0
Stock-based expense	16,282	15,086	12,201
Bad debt expense (recovery)	(63)	93	3,155
Excess tax benefit related to stock-based expense	0	0	(6)
Amortization of deferred financing costs	235	235	98
Other non-cash expense	(240)	73	151
Changes in operating assets and liabilities:
Accounts receivable	(4,053)	9,842	(13,589)
Prepaid expenses and other current assets	1,271	187	(165)
Other non-current assets	630	(1,531)	(177)
Accounts payable	(1,816)	2,401	(297)
Accrued expenses and other current liabilities	(2,491)	(4,428)	(1,165)
Deferred revenue	6,980	2,286	6,258
Other liabilities, long-term	(669)	6,204	(2,599)
Net cash provided by (used in) operating activities	14,765	19,717	(16,566)
Investing activities:
Proceeds from sale of discontinued operations	0	4,501	25,500
Purchases of property, equipment and capitalized internal-use software development costs	(9,098)	(23,982)	(11,438)
Decrease in restricted cash	0	0	500
Purchases of short-term investments	(44,574)	(61,834)	(82,770)
Proceeds from maturities of short-term investments	56,297	63,650	65,681
Proceeds from sale of short-term investments	0	0	5,012
Net cash provided by (used in) investing activities	2,625	(17,665)	2,485
Financing activities:
Proceeds from employee stock compensation plans	1,786	3,027	7,545
Proceeds from revolving line of credit	0	0	57,000
Payments on revolving line of credit	(10,000)	(15,000)	(27,000)
Deferred financing costs	0	0	(706)
Excess tax benefit related to stock-based expense	0	0	6
Net cash provided by (used in) financing activities	(8,214)	(11,973)	36,845
Effect of exchange rate fluctuations on cash and cash equivalents	(645)	(157)	(657)
Net change in cash and cash equivalents	8,531	(10,078)	22,107
Cash and cash equivalents at beginning of period	43,963	54,041	31,934
Cash and cash equivalents at end of period	52,494	43,963	54,041
Supplemental disclosure of other cash flow information:
Cash paid for income taxes, net of refunds	724	1,071	902
Cash paid for interest	1,609	2,132	1,418
Supplemental disclosure of non-cash investing and financing activities:
Purchase of fixed assets recorded in accounts payable	0	180	282
Asset retirement obligation costs incurred	0	100	532
Capitalized stock-based compensation	$ 495	$ 488	$ 601