Income Taxes - NOL and tax credits (Details) - USD ($)
$ in Thousands |
12 Months Ended |
|
|
Mar. 31, 2018 |
Mar. 31, 2017 |
Mar. 31, 2018 |
Mar. 31, 2017 |
| Other disclosures |
|
|
|
|
| Total amount of unrecognized tax benefits |
$ 2,825
|
$ 2,701
|
$ 2,467
|
$ 2,825
|
| Interest or penalties related to unrecognized tax benefits |
|
|
0
|
0
|
| Unrecognized tax benefits, that if recognized, would affect the effective tax rate |
|
|
2,500
|
2,800
|
| Reconciliation of the beginning and ending amount of total gross unrecognized tax benefits |
|
|
|
|
| Balance at the beginning of the period |
2,825
|
2,701
|
|
|
| Gross increase related to current year tax positions |
|
124
|
|
|
| Lapse of statute of limitations |
(358)
|
|
|
|
| Balance at the end of the period |
2,467
|
2,825
|
|
|
| Maximum |
|
|
|
|
| NOL and tax credit carry forwards for federal and state income tax purposes |
|
|
|
|
| Annual limitation amount on utilization of the NOLs and tax credits |
|
|
57,300
|
|
| Research and development |
|
|
|
|
| Other disclosures |
|
|
|
|
| Total amount of unrecognized tax benefits |
2,800
|
2,800
|
2,500
|
2,800
|
| Reconciliation of the beginning and ending amount of total gross unrecognized tax benefits |
|
|
|
|
| Balance at the beginning of the period |
2,800
|
|
|
|
| Balance at the end of the period |
$ 2,500
|
$ 2,800
|
|
|
| Federal |
|
|
|
|
| NOL and tax credit carry forwards for federal and state income tax purposes |
|
|
|
|
| NOL |
|
|
657,752
|
|
| Tax credit carry forwards |
|
|
8,971
|
|
| Other disclosures |
|
|
|
|
| Deferred tax assets related to research and development credits |
|
|
9,000
|
10,200
|
| State |
|
|
|
|
| NOL and tax credit carry forwards for federal and state income tax purposes |
|
|
|
|
| NOL |
|
|
146,628
|
|
| Tax credit carry forwards |
|
|
9,692
|
|
| Other disclosures |
|
|
|
|
| Deferred tax assets related to research and development credits |
|
|
$ 10,200
|
$ 9,800
|