Long-Term Debt (Convertible Debt Instruments and Terms) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 Days
Subordinated Convertible Notes Due 2029 [Member]
Debt Instrument [Line Items]
Consecutive trading days	30
Contingent, conversion price	$ 47.78
Debt instrument, beginning date	Aug. 31, 2029
Conversion price per share	$ 36.75
Conversion, shares per $1,000 principal amount of notes	27.2109
Principal amount of notes	$ 1,000
Common stock covered under note hedges	11,686,075
Subordinated Convertible Notes Due 2029 [Member] | Make-Whole [Member]
Debt Instrument [Line Items]
Common stock covered under note hedges	14,315,419
Subordinated Convertible Notes Due 2029 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Trading days	20
1.00% Senior Convertible Notes Due 2012 [Member]
Debt Instrument [Line Items]
Consecutive trading days	30
Contingent, conversion price	$ 109.11
Debt instrument, beginning date	Sep. 15, 2012
Conversion price per share	$ 83.93
Conversion, shares per $1,000 principal amount of notes	11.9142
Principal amount of notes	1,000
Common stock covered under note hedges	5,659,245
1.00% Senior Convertible Notes Due 2012 [Member] | Make-Whole [Member]
Debt Instrument [Line Items]
Common stock covered under note hedges	7,215,535
1.00% Senior Convertible Notes Due 2012 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Trading days	20
0.875% Convertible Notes Due 2013 [Member]
Debt Instrument [Line Items]
Consecutive trading days	30
Contingent, conversion price	$ 65.47
Debt instrument, beginning date	Oct. 15, 2013
Conversion price per share	$ 50.36
Conversion, shares per $1,000 principal amount of notes	19.856
Principal amount of notes	$ 1,000
Common stock covered under note hedges	7,048,880
0.875% Convertible Notes Due 2013 [Member] | Make-Whole [Member]
Debt Instrument [Line Items]
Common stock covered under note hedges	8,987,322
0.875% Convertible Notes Due 2013 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Trading days	20