Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 7,522	$ 6,139
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	2,606	2,049
Share-based compensation expense	1,710	1,350
Provision for doubtful accounts	486	190
Gain on sale of property and equipment	(3)	(110)
Foreign currency gains, net	(387)	(441)
Excess tax benefits from stock option exercises	(1,783)
Net change in operating assets and liabilities:
Accounts receivable	(6,995)	447
Prepaid expenses and other current assets	1,625	263
Other long-term assets	(326)	(210)
Accounts payable	(2,524)	(3,267)
Accrued employee compensation and benefits	(4,842)	(5,146)
Accrued expenses and other current liabilities	(178)	10
Income taxes payable	1,310	1,035
Other long-term liabilities	(4)	65
Net cash (used in) provided by operating activities	(1,783)	2,374
Cash flows from investing activities:
Proceeds from sale of property and equipment	11	116
Purchase of short-term investments	(1,401)	(2,290)
Proceeds from sale or maturity of short-term investments	1,800	837
Purchase of long-term investments	(3,858)	(2,946)
Proceeds from sale or maturity of long-term investments	600	200
Increase in restricted cash	(10)	(306)
Purchase of property and equipment	(1,678)	(3,116)
Net cash used in investing activities	(4,536)	(7,505)
Cash flows from financing activities:
Proceeds from exercise of common stock options	1,293	132
Purchases of common stock		(1,408)
Principal payments on capital lease obligation	(5)	(1,018)
Excess tax benefits from stock option exercises	1,783
Net cash provided by (used in) financing activities	3,071	(2,294)
Effect of exchange rate changes on cash and cash equivalents	(2,983)	(2,501)
Net decrease in cash and cash equivalents	(6,231)	(9,926)
Cash and cash equivalents, beginning of period	57,199	58,105
Cash and cash equivalents, end of period	$ 50,968	$ 48,179