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Debt and Credit Arrangements - 2024 Convertible Notes (Details)
$ / shares in Units, shares in Thousands
1 Months Ended 12 Months Ended
Dec. 31, 2017
USD ($)
Dec. 31, 2021
USD ($)
day
$ / shares
Dec. 31, 2020
USD ($)
Nov. 06, 2017
USD ($)
Oct. 31, 2017
$ / shares
shares
Debt Instrument          
Share price (usd per share) | $ / shares   $ 159.49      
Convertible Debt | Convertible Notes, due 2024          
Debt Instrument          
Debt instrument stated interest rate (percent)   1.00%   1.00%  
Principal amount   $ 258,800,000 $ 258,800,000 $ 258,800,000  
Share conversion rate   0.0170285      
Debt instrument, conversion price (usd per share) | $ / shares         $ 58.725
Debt instrument, conversion premium (percentage)   35.00%      
Share price (usd per share) | $ / shares         $ 43.50
Value of securities above principal amount of debt if converted   $ 444,000,000.0      
Debt instrument, threshold for trading days | day   20      
Debt instrument, threshold for consecutive trading days | day   30      
Applicable conversion price threshold (as percentage)   130.00%      
Maximum days after five trading days   5 days      
Applicable conversion price, less than (as percentage)   97.00%      
Trigger price (usd per share) | $ / shares   $ 76.3425      
Debt instrument effective interest rate       4.80%  
Non cash payment for derivative instrument $ 59,500,000        
Number of shares underlying warrant (shares) | shares         4,410
Proceeds from issuance of warrants $ 46,000,000.0        
Percentage above previous sales price         65.00%
Net cost of convertible note hedge and warrant   $ 13,500,000      
Convertible Debt | Convertible Notes, due 2024 | Maximum          
Debt Instrument          
Debt instrument, conversion price (usd per share) | $ / shares   $ 71.775     $ 71.775
Convertible Debt | Convertible Notes, due 2024 | Liability Component          
Debt Instrument          
Principal amount       $ 200,100,000  
Debt issuance costs       5,300,000  
Convertible Debt | Convertible Notes, due 2024 | Equity Component          
Debt Instrument          
Principal amount       58,700,000  
Debt issuance costs       $ 1,500,000