Revenue from Contracts with Customers - Summary of Impact of Adoption of ASC 606 on Consolidated Balance Sheet and Consolidated Statements of Net Income and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018	Apr. 01, 2018
ASSETS
Accounts receivable, net	$ 80,006				$ 87,459				$ 80,006	$ 87,459	$ 84,962
Contract assets	12,529				13,242				12,529	13,242
Income taxes receivable	856				3,682				856	3,682
Prepaid expenses and other current assets	26,305				20,946				26,305	20,946	17,360
Deferred income taxes, net	10,620				6,194				10,620	6,194	9,219
Contract assets, net of current	3,007				3,747				3,007	3,747
Other assets	33,656				32,478				33,656	32,478	18,795
LIABILITIES
Contract liabilities	56,786				56,009				56,786	56,009	54,079
Accrued compensation and related benefits	23,792				25,663				23,792	25,663	27,910
Other current liabilities	41,352				41,064				41,352	41,064	48,317
Contract liabilities, net of current											1,173
Shareholders' equity:
Retained earnings	119,119				111,621				119,119	111,621	78,708
Revenues:
Total revenues	136,382	$ 137,740	$ 134,256	$ 131,861	134,785	$ 130,867	$ 130,321	$ 133,200	540,239	529,173	531,019
Total cost of revenue	68,339	68,135	65,734	65,231	62,057	61,671	61,118	61,851	267,439	246,697	241,535
Gross profit	68,043	69,605	68,522	66,630	72,728	69,196	69,203	71,349	272,800	282,476	289,484
Operating expenses:
Selling, general and administrative	43,159	42,841	39,046	40,128	44,710	41,304	34,229	44,636	165,174	164,879	193,226
Research and development costs, net	21,429	20,026	19,789	22,051	19,813	20,682	18,371	22,128	83,295	80,994	81,259
Amortization of acquired intangible assets	1,449	964	865	865	1,028	1,027	1,121	1,168	4,143	4,344	7,810
Restructuring costs	77	546	175	1,707	640				2,505	640	611
Total operating expenses	74,332	66,325	61,791	65,240	66,191	63,013	53,721	67,932	267,688	250,857	286,663
Income from operations	(6,289)	3,280	6,731	1,390	6,537	6,183	15,482	3,417	5,112	31,619	2,821
Interest and other income, net										(2,331)
Income before provision for (benefit of) income taxes	(6,207)	3,012	6,590	864	5,928	5,280	14,990	3,090	4,259	29,288	(410)
Provision for income taxes	(1,965)	(1,403)	509	(380)	2,000	456	1,896	442	(3,239)	4,794	(2,830)
Net income	$ (4,242)	$ 4,415	$ 6,081	$ 1,244	3,928	$ 4,824	$ 13,094	$ 2,648	$ 7,498	24,494	$ 2,420
Recurring
Revenues:
Total revenues										473,921
Software, Hardware, and Other Non-recurring
Revenues:
Total revenues										55,252
Adoption of ASC 606
ASSETS
Accounts receivable, net												$ 87,342
Contract assets												13,446
Prepaid expenses and other current assets												17,137
Deferred income taxes, net												6,335
Contract assets, net of current												2,731
Other assets												25,474
LIABILITIES
Contract liabilities												58,253
Accrued compensation and related benefits												28,655
Other current liabilities												58,281
Shareholders' equity:
Retained earnings												87,127
Adoption of ASC 606 | ASC 606 Transition Adjustments
ASSETS
Accounts receivable, net					1,220					1,220		2,380
Contract assets					(13,242)					(13,242)		13,446
Income taxes receivable					409					409
Prepaid expenses and other current assets					692					692		(223)
Deferred income taxes, net					4,457					4,457		(2,884)
Contract assets, net of current					(3,747)					(3,747)		2,731
Other assets					(12,611)					(12,611)		6,679
LIABILITIES
Contract liabilities					(1,348)					(1,348)		4,174
Accrued compensation and related benefits					712					712		745
Other current liabilities					(7,838)					(7,838)		9,964
Contract liabilities, net of current					888					888		(1,173)
Shareholders' equity:
Retained earnings					(15,236)					(15,236)		$ 8,419
Revenues:
Total revenues										(1,878)
Total cost of revenue										159
Gross profit										(2,037)
Operating expenses:
Selling, general and administrative										6,762
Total operating expenses										6,762
Income from operations										(8,799)
Income before provision for (benefit of) income taxes										(8,799)
Provision for income taxes										(1,982)
Net income										(6,817)
Adoption of ASC 606 | ASC 606 Transition Adjustments | Recurring
Revenues:
Total revenues										(430)
Adoption of ASC 606 | ASC 606 Transition Adjustments | Software, Hardware, and Other Non-recurring
Revenues:
Total revenues										(1,448)
Adoption of ASC 606 | Calculated under Revenue Guidance in Effect before Topic 606
ASSETS
Accounts receivable, net					88,679					88,679
Income taxes receivable					4,091					4,091
Prepaid expenses and other current assets					21,638					21,638
Deferred income taxes, net					10,651					10,651
Other assets					19,867					19,867
LIABILITIES
Contract liabilities					54,661					54,661
Accrued compensation and related benefits					26,375					26,375
Other current liabilities					33,226					33,226
Contract liabilities, net of current					888					888
Shareholders' equity:
Retained earnings					$ 96,385					96,385
Revenues:
Total revenues										527,295
Total cost of revenue										246,856
Gross profit										280,439
Operating expenses:
Selling, general and administrative										171,641
Research and development costs, net										80,994
Amortization of acquired intangible assets										4,344
Restructuring costs										640
Total operating expenses										257,619
Income from operations										22,820
Interest and other income, net										(2,331)
Income before provision for (benefit of) income taxes										20,489
Provision for income taxes										2,812
Net income										17,677
Adoption of ASC 606 | Calculated under Revenue Guidance in Effect before Topic 606 | Recurring
Revenues:
Total revenues										473,491
Adoption of ASC 606 | Calculated under Revenue Guidance in Effect before Topic 606 | Software, Hardware, and Other Non-recurring
Revenues:
Total revenues										$ 53,804