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Debt and Other Financing Arrangements - Additional Information (Details)
Jun. 17, 2013
USD ($)
trading_day
$ / shares
shares
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Debt Instrument [Line Items]      
Payments for convertible note hedges $ (49,500,000)    
Proceeds from the issuance of warrants $ 23,200,000    
Note hedges on common stock (in shares) | shares 4,700,000    
Number of shares purchasable upon warrant exercise (in shares) | shares 4,700,000    
Warrants exercise price (usd per share) | $ / shares $ 80.06    
Convertible Debt      
Debt Instrument [Line Items]      
Debt issued, senior convertible notes $ 253,000,000    
Interest rate on convertible notes issued 1.50%    
Conversion rate on convertible debt 18.5046    
Conversion price on convertible debt (usd per share) | $ / shares $ 54.04    
Debt recorded $ 214,300,000 $ 240,450,000 $ 232,583,000
Adjustments for equity component of convertible debt (38,700,000)    
Debt issuance cost 7,300,000    
Unamortized debt issuance expense 6,200,000    
Issuance cost allocated to equity components 1,100,000    
Effective interest rate   5.40%  
Proceeds from issuance of debt $ 246,000,000    
Convertible Debt | Prior to April 1, 2018 | Maximum      
Debt Instrument [Line Items]      
Trading day threshold on convertible debt | trading_day 20    
Consecutive trading day threshold on convertible debt 30 days    
Stock price threshold, convertible debt 130.00%    
Convertible Debt | Prior to April 1, 2018 | Minimum      
Debt Instrument [Line Items]      
Trading day threshold on convertible debt | trading_day 5    
Consecutive trading day threshold on convertible debt 5 days    
Stock price threshold, convertible debt 98.00%