Stock Options (Aggregate Activity Under Stock Option Plans) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Stock Options Aggregate Activity Under Stock Option Plans Details
Options outstanding at beginning of year	6,656,000
Options granted	719,000
Options exercised	499,000
Options forfeited/expired	209,000
Options outstanding at March 31, 2014	6,667,000
Weighted-average exercise price of options outstanding, beginning of year	$ 8.03
Weighted-average exercise price of options granted during period	$ 37.59
Weighted-average exercise price of options exercised during the period	$ 8.70
Weighted-average exercise price of options forfeited/expired during the period	$ 5.25
Weighted-average exercise price of options outstanding, at March 31, 2014	$ 11.25
Weighted-average remaining contractual term of options outstanding, at March 31, 2014	7 years 252 days
Aggregate intrinsic value of options outstanding, at March 31, 2014	$ 129,980
Options Vested and Expected to Vest, Number of Shares	6,241,000
Options Vested and Expected to Vest, Weighted-Average Exercise Price Per Share	$ 10.79
Options Vested and Expected to Vest, Weighted-Average Remaining Contractual Term	7 years 219 days
Options Vested and Expected to Vest, Aggregate Intrinsic Value	124,041
Options Exercisable, Number of Shares	3,098,000
Options Exercisable, Weighted-Average Exercise Price Per Share	$ 6.37
Options Exercisable, Weighted-Average Remaining Contractual Term	6 years 157 days
Options Exercisable, Aggregate Intrinsic Value	$ 72,989