Financial Instruments and Fair Value Measurement (Tables)
 3 Months Ended
Mar. 31, 2015
Fair Value Disclosures [Abstract]  
Assets and liabilities measured at fair value on recurring basis
 
Balance at
March 31, 2015
 
Quoted Price in
Active Markets for
Identical Assets
(Level 1)
 
Significant
Other Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
Assets:
 
 
 
 
 
 
 
Available-for-sale securities
$
2,945.8

 
$
967.1

 
$
1,978.7

 
$
—

Forward currency contracts
901.8

 
—

 
901.8

 
—

Purchased currency options
25.3

 
—

 
25.3

 
—

Interest rate swaps
32.8

 
—

 
32.8

 
—

Total assets
$
3,905.7

 
$
967.1

 
$
2,938.6

 
$
—

Liabilities:
 

 
 

 
 

 
 

Contingent value rights
$
(128.5
)
 
$
(128.5
)
 
$
—

 
$
—

Written currency options
(3.8
)
 
—

 
(3.8
)
 
—

Other acquisition related contingent consideration
(1,305.8
)
 
—

 
—

 
(1,305.8
)
Total liabilities
$
(1,438.1
)
 
$
(128.5
)
 
$
(3.8
)
 
$
(1,305.8
)
 
 
 
 
 
 
 
 
 
Balance at
December 31, 2014
 
Quoted Price in
Active Markets for
Identical Assets
(Level 1)
 
Significant
Other Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
Assets:
 

 
 

 
 

 
 

Available-for-sale securities
$
3,425.1

 
$
1,051.3

 
$
2,373.8

 
$
—

Forward currency contracts
550.7

 
—

 
550.7

 
—

Purchased currency options
9.8

 
—

 
9.8

 
—

Interest rate swaps
20.0

 
—

 
20.0

 
—

Total assets
$
4,005.6

 
$
1,051.3

 
$
2,954.3

 
$
—

Liabilities:
 

 
 

 
 

 
 

Contingent value rights
$
(136.3
)
 
$
(136.3
)
 
$
—

 
$
—

Written currency options
(4.6
)
 
—

 
(4.6
)
 
—

Other acquisition related contingent consideration
(1,279.0
)
 
—

 
—

 
(1,279.0
)
Total liabilities
$
(1,419.9
)
 
$
(136.3
)
 
$
(4.6
)
 
$
(1,279.0
)
Roll-forward of fair value of Level 3 instruments (significant unobservable inputs), liabilities
The following table represents a roll-forward of the fair value of Level 3 instruments: 
 
Three-Month Periods Ended March 31,
 
2015
 
2014
Liabilities:
 

 
 

Balance at beginning of period
$
(1,279.0
)
 
$
(228.5
)
Amounts acquired or issued
—

 
—

Net change in fair value
(26.8
)
 
(5.2
)
Settlements
—

 
20.0

Transfers in and/or out of Level 3
—

 
—

Balance at end of period
$
(1,305.8
)
 
$
(213.7
)