v2.4.0.8
Subsidiary Preferred Stock (Details) (Series A Preferred Stock, NCPS, USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
item
Series A Preferred Stock | NCPS
  
Subsidiary preferred stock  
Subsidiary preferred stock, shares outstanding 75,000
Subsidiary Preferred Stock, par value (in dollars per share) $ 0.01
Subsidiary Preferred Stock, shares authorized 10,000,000
Cumulative dividends per annum on preferred stock (in dollars per share) $ 40.00
Liquidation value (in dollars per share) $ 1,000
Liquidation preference (in dollars) $ 75.0
Redemption price of preferred stock (as a percent) 101.00%
Conversion price of preferred stock into Superior common stock (in shares) 22.12
Conversion price of preferred stock (in dollars per share) $ 25.00
Conversion rate of preferred stock into deemed common shares (in shares) 40
Number of deemed common shares in conversion 3,000,000
Redemption value of preferred stock $ 75.8
Number of voter per share entitled under preferred stock voting rights 1