Annual report pursuant to Section 13 and 15(d)

Income Taxes - NOL and tax credits (Details)

v3.8.0.1
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