Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Stockholder Rights Plan (Details)

v3.8.0.1
Stock-Based Compensation - Stockholder Rights Plan (Details)
May 06, 2016
Vote
$ / shares
Dec. 31, 2017
$ / shares
Mar. 31, 2017
$ / shares
Stockholder Rights Plan      
Preferred stock, par value (in dollars per share)   $ 0.001 $ 0.001
Series B Junior Participating Preferred Stock      
Stockholder Rights Plan      
Preferred share purchase rights period 30 days    
Preferred share purchase right ratio 1    
Preferred stock conversion basis 0.001    
Preferred stock, par value (in dollars per share) $ 0.001    
Purchase price (in dollars per share) $ 8.76    
Period following public announcement of beneficial ownership acquired by various persons resulting in rights becoming exercisable 10 days    
Period following commencement of tender offer or exchange offer that would result in acquisition of beneficial ownership various persons resulting in rights becoming exercisable 10 days    
Preferred stock dividend minimum if declared $ 1.00    
Preferred stock rights ratio over common stock 1,000    
Number of votes per share | Vote 1,000    
Ratio of consideration received in event of conversion or exchange transaction 1,000    
Series B Junior Participating Preferred Stock | Minimum      
Stockholder Rights Plan      
Beneficial ownership of common stock (as a percent) 4.99%