Impairment and Restructuring Charges	6 Months Ended
	Sep. 30, 2021
Impairment and Restructuring Charges [Abstract]
Impairment and Restructuring Charges	6.     Impairment and Restructuring Charges Long-lived Assets and Right of Use Assets Impairment. During the three and six months ended September 30, 2021, the Company recorded $0.1 million for both periods in non-cash impairment charges to reduce the carrying values to zero for long-lived assets consisting of network equipment. During the six months ended September 30, 2020, the Company recorded a $29,000 non-cash impairment charge to reduce the carrying values to zero for long-lived assets consisting of network site costs. There was no impairment charge for the three months ended September 30, 2020. Restructuring Charges. December 2018 cost reductions. On December 31, 2018, the Company’s board of directors approved the following cost reduction actions: (i) the elimination of approximately 20 positions, or 30% of the Company’s workforce and (ii) the closure of its office in San Diego, California (collectively, the “December 2018 Cost-Reduction Actions”). For the three and six months ended September 30, 2020, the Company reduced restructuring charges relating to the December 2018 Cost-Reduction Actions in the amounts of $17,000 and $3,000, respectively, related to employee severance and benefit costs. The Company did not incur restructuring charges for the three and six months ended September 30, 2021.