Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2013	Jul. 31, 2012
Operating activities:
Net loss	$ (17,368)	$ (18,539)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization expense	3,476	1,713
Stock-based expense	4,008	12,338
Bad debt expense	566	153
Excess tax benefit related to stock-based expense	(90)	(82)
Changes in operating assets and liabilities:
Accounts receivable	2,507	1,129
Prepaid expenses and other current assets	(356)	442
Other non-current assets	(523)	57
Accounts payable	(474)	2,086
Accrued expenses and other current liabilities	1,729	(1,044)
Deferred revenue	(2,432)	(276)
Other liabilities, long-term	(239)	201
Net cash used in operating activities	(9,196)	(1,822)
Investing activities:
Acquisitions, net of cash acquired, and purchase of intangible asset	(205)	(30,313)
Purchases of property, equipment and capitalized internal-use software development costs	(3,963)	(3,196)
Purchases of short-term investments	(25,161)	(24,126)
Proceeds from maturities of short-term investments	21,250	277
Proceeds from sales of short-term investments	16,100
Net cash provided by (used in) investing activities	8,021	(57,358)
Financing activities:
Proceeds from follow-on stock offering, net of costs		52,184
Proceeds from employee stock compensation plans	2,837	780
Excess tax benefit related to stock-based expense	90	82
Net cash provided by financing activities	2,927	53,046
Effect of exchange rate fluctuations on cash and cash equivalents	(57)	(88)
Net change in cash and cash equivalents	1,695	(6,222)
Cash and cash equivalents at beginning of period	25,045	74,367
Cash and cash equivalents at end of period	26,740	68,145
Supplemental disclosure of other cash flow information:
Cash paid for income taxes	357	236
Supplemental disclosure of non-cash investing and financing activities:
Accrued stock offering costs		246
Issuance of stock for acquisition		$ 119,696