Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.7.0.1
Income Taxes (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Increase (decrease) in valuation allowance $ 10.5 $ 12.3
Internal Revenue Service I R S [Member]    
Net operating loss carryforwards 146.8  
Internal Revenue Service I R S [Member] | Research [Member]    
Tax credit carryforwards $ 1.5  
Internal Revenue Service I R S [Member] | Minimum [Member]    
Expiration year Dec. 31, 2021  
Internal Revenue Service I R S [Member] | Minimum [Member] | Research [Member]    
Expiration year Dec. 31, 2022  
Internal Revenue Service I R S [Member] | Maximum [Member]    
Expiration year Dec. 31, 2036  
Internal Revenue Service I R S [Member] | Maximum [Member] | Research [Member]    
Expiration year Dec. 31, 2036  
State And Local Jurisdiction [Member]    
Net operating loss carryforwards $ 137.0  
State And Local Jurisdiction [Member] | Research [Member]    
Tax credit carryforwards $ 2.3  
State And Local Jurisdiction [Member] | Minimum [Member]    
Expiration year Dec. 31, 2017  
State And Local Jurisdiction [Member] | Maximum [Member]    
Expiration year Dec. 31, 2036