XML 86 R54.htm IDEA: XBRL DOCUMENT v2.4.0.8
Subsequent Events - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 6 Months Ended 1 Months Ended 6 Months Ended 1 Months Ended
Jun. 30, 2013
Nov. 30, 2009
4.50% Convertible senior notes (due 2014)
Jun. 30, 2013
4.50% Convertible senior notes (due 2014)
Jul. 24, 2013
Subsequent Event
4.25% Convertible Senior Notes due 2018
Jul. 24, 2013
Subsequent Event
4.50% Convertible senior notes (due 2014)
Subsequent Event [Line Items]          
Long term debt, face amount   $ 100.0   $ 100.0  
Debt instrument, interest rate   4.50%   4.25% 4.50%
Debt instrument, maturity date Apr. 02, 2013 Nov. 01, 2014 Nov. 01, 2014 Aug. 01, 2018  
Frequency of interest payment   Semi-annually   Semi-annually  
Conversion rate in share per $1000 principal amount of notes   63.2091   114.3674  
Debt instrument, conversion rate   $ 15.82   $ 8.74  
Principal amount of additional notes       15.0  
Net proceeds from debt instrument         95.9
Debt instrument repurchase amount         $ 61.0