Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Revenue	$ 2,102,781	$ 2,101,299	$ 1,960,478
Digital
Disaggregation of Revenue [Line Items]
Revenue	1,433,648	1,359,327	1,255,335
Print
Disaggregation of Revenue [Line Items]
Revenue	669,133	741,972	705,143
Re-occurring Revenue
Disaggregation of Revenue [Line Items]
Revenue	1,540,967	1,456,841	1,314,549
Transactional Revenue
Disaggregation of Revenue [Line Items]
Revenue	561,814	644,458	645,929
Operating Segments \| K-12
Disaggregation of Revenue [Line Items]
Revenue	884,480	970,484	904,855
Operating Segments \| Higher Education
Disaggregation of Revenue [Line Items]
Revenue	878,954	782,610	702,187
Operating Segments \| Global Professional
Disaggregation of Revenue [Line Items]
Revenue	150,076	149,588	153,079
Operating Segments \| International
Disaggregation of Revenue [Line Items]
Revenue	186,685	201,402	200,464
Operating Segments \| Digital \| K-12
Disaggregation of Revenue [Line Items]
Revenue	429,644	430,546	425,786
Operating Segments \| Digital \| Higher Education
Disaggregation of Revenue [Line Items]
Revenue	799,898	723,066	633,762
Operating Segments \| Digital \| Global Professional
Disaggregation of Revenue [Line Items]
Revenue	107,120	102,996	97,202
Operating Segments \| Digital \| International
Disaggregation of Revenue [Line Items]
Revenue	96,986	102,719	98,585
Operating Segments \| Print \| K-12
Disaggregation of Revenue [Line Items]
Revenue	454,836	539,938	479,069
Operating Segments \| Print \| Higher Education
Disaggregation of Revenue [Line Items]
Revenue	79,056	59,544	68,425
Operating Segments \| Print \| Global Professional
Disaggregation of Revenue [Line Items]
Revenue	42,956	46,592	55,877
Operating Segments \| Print \| International
Disaggregation of Revenue [Line Items]
Revenue	89,699	98,683	101,879
Operating Segments \| Re-occurring Revenue \| K-12
Disaggregation of Revenue [Line Items]
Revenue	619,725	602,040	553,856
Operating Segments \| Re-occurring Revenue \| Higher Education
Disaggregation of Revenue [Line Items]
Revenue	734,353	666,748	584,837
Operating Segments \| Re-occurring Revenue \| Global Professional
Disaggregation of Revenue [Line Items]
Revenue	98,746	95,094	87,938
Operating Segments \| Re-occurring Revenue \| International
Disaggregation of Revenue [Line Items]
Revenue	88,143	92,959	87,918
Operating Segments \| Transactional Revenue \| K-12
Disaggregation of Revenue [Line Items]
Revenue	264,755	368,444	350,999
Operating Segments \| Transactional Revenue \| Higher Education
Disaggregation of Revenue [Line Items]
Revenue	144,601	115,862	117,350
Operating Segments \| Transactional Revenue \| Global Professional
Disaggregation of Revenue [Line Items]
Revenue	51,330	54,494	65,141
Operating Segments \| Transactional Revenue \| International
Disaggregation of Revenue [Line Items]
Revenue	98,542	108,443	112,546
Other
Disaggregation of Revenue [Line Items]
Revenue	2,586	(2,785)	(107)
Other \| Digital
Disaggregation of Revenue [Line Items]
Revenue	0	0	0
Other \| Print
Disaggregation of Revenue [Line Items]
Revenue	2,586	(2,785)	(107)
Other \| Re-occurring Revenue
Disaggregation of Revenue [Line Items]
Revenue	0	0	0
Other \| Transactional Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 2,586	$ (2,785)	$ (107)