v2.4.0.6
Borrowings (Narrative) (Details) (USD $)
 3 Months Ended 1 Months Ended 3 Months Ended
Mar. 31, 2013
item
Mar. 31, 2012
Dec. 31, 2012
Nov. 30, 2011
Institutional And Accredited Investor [Member]
Mar. 31, 2013
Institutional And Accredited Investor [Member]
Mar. 31, 2013
Loss On Conversion Of Notes [Member]
Debt Instrument [Line Items]            
Interest rate       5.50%    
Private placement of senior convertible notes $ 48,340,000   $ 90,960,000 $ 152,000,000    
Issuance costs 6,634,000          
Proceeds from issuance of notes 145,366,000          
Converted number of common stock shares 69.9032          
Initial conversion rate $ 14.31          
Amount of notes converted 42,060,000          
Common stock converted, shares 2,979,000          
Loss on conversion of convertible debt 5,715,000          
Interest and other expense, net 10,067,000 2,682,000       5,715,000
Debt instrument periodic payment       payable in cash semi-annually on June 15 and December 15 of each year    
Convertible Senior Notes principal amount $ 1          
Number shares that the notes are convertible 3,379,000          
Maturity date         Dec. 15, 2016  
Notes issued with an effective yield 5.96%          
Original issue discount 98.00%          
Redeemable convertible securities maximum, shares 4,308,000          
Redeemable convertible securities price per share $ 11.22