Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Deficit - Additional Information (Detail)

v3.2.0.727
Shareholders' Deficit - Additional Information (Detail) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 1 Months Ended 2 Months Ended 3 Months Ended 6 Months Ended
May. 07, 2014
Feb. 28, 2014
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Mar. 31, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Feb. 03, 2014
Jul. 30, 2012
Stockholders Equity [Line Items]                      
Dividends paid       $ 0.0 $ 0.0   $ 0.0 $ 30.4      
Dividends received primarily relating to forward transactions       0.0 0.0   $ 0.0 3.4      
Share repurchase program authorized amount                   $ 1,500.0 $ 1,000.0
Share repurchase program expiration date             Jul. 30, 2017        
Retained earnings       (504.4)     $ (504.4)   $ (665.4)    
Additional paid-in-capital       426.3     426.3   $ 409.1    
Non-cash forward transaction issuance costs           $ 35.8          
Non-cash interest expense       $ 1.6 1.6   3.2 2.6      
Repurchase of common stock, amount $ 266.0           $ 9.1 1,277.9      
Repurchase of common stock, shares     4.3 0.0     0.0        
Amounts reclassified from accumulated other comprehensive income (loss) to income, tax expense unrealized gain (loss) on available-for-sale investments             $ 0.8 1.0      
Foreign Currency Translation Adjustments [Member]                      
Stockholders Equity [Line Items]                      
Other comprehensive income (loss) before reclassifications, Tax expense (benefits)       $ (2.4) 1.6   (4.3) 1.5      
Unrealized Gain (Loss) on Derivatives [Member]                      
Stockholders Equity [Line Items]                      
Other comprehensive income (loss) before reclassifications, Tax expense (benefits)       (0.1) (0.2)   0.5 (0.3)      
Unrealized Gain (Loss) on Available-For-Sale Investments [Member]                      
Stockholders Equity [Line Items]                      
Other comprehensive income (loss) before reclassifications, Tax expense (benefits)         $ 0.1   (1.0) $ (0.9)      
Unrealized Gain (Loss) on Derivatives [Member]                      
Stockholders Equity [Line Items]                      
Amounts reclassified from accumulated other comprehensive income (loss) to income, tax benefits unrealized gain (loss) on derivatives       $ (0.2)     $ (0.2)        
Convertible Notes [Member]                      
Stockholders Equity [Line Items]                      
Convertible notes initial conversion price     $ 86.28 $ 86.28 $ 86.28   $ 86.28 $ 86.28      
Capped call transactions [Member]                      
Stockholders Equity [Line Items]                      
Capped call transactions with financial institutions   $ 123.8                  
Capped call transactions price per common share   $ 120.79                  
Increase (decrease) in additional paid-in capital, other           (123.8)          
Capped call transactions [Member] | Convertible Notes [Member]                      
Stockholders Equity [Line Items]                      
Convertible notes initial conversion price   $ 86.28                  
Repurchase Agreement 2014 [Member]                      
Stockholders Equity [Line Items]                      
Agreement expiration date             Jun. 30, 2014        
Prepaid forward share repurchase transactions [Member]                      
Stockholders Equity [Line Items]                      
Forward share repurchase transactions amount   $ 685.8       $ 685.8          
Share repurchase transaction, shares to be purchased   9.9       9.9          
Settlement date of forward transactions             Aug. 15, 2019        
Retained earnings           $ (653.9)          
Additional paid-in-capital           $ (31.9)          
Average cost per share of shares repurchased           $ 69.02          
Share repurchase program, remaining authorized capacity       $ 232.9     $ 232.9        
Open market purchases [Member]                      
Stockholders Equity [Line Items]                      
Repurchase of common stock, shares         9.8            
Shares repurchased aggregate cost         $ 581.3            
Average cost per share of shares repurchased         $ 59.41