Share-Based Compensation (Schedule of Stock Option Activity) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Number of Options
Outstanding, at beginning of year (in shares) | shares	2,311
Granted (in shares) | shares	220
Exercised (in shares) | shares	(562)
Forfeited (in shares) | shares	(16)
Outstanding, at end of year (in shares) | shares	1,953
Fully vested, at end of year (in shares) | shares	1,057
Fully vested and expected to vest, at end of year (in shares) | shares	1,933
Weighted Average Exercise Price
Weighted average exercise price of beginning balance of options outstanding (in USD per share) | $ / shares	$ 117.13
Weighted average exercise price of options granted (in USD per share) | $ / shares	291.14
Weighted average exercise price of options exercised (in USD per share) | $ / shares	71.65
Weighted average exercise price of options forfeited (in USD per share) | $ / shares	180.78
Weighted average exercise price of ending balance of options outstanding (in USD per share) | $ / shares	149.32
Weighted average exercise price of options fully vested (in USD per share) | $ / shares	106.91
Weighted average exercise price of options fully vested and expected to vest (in USD per share) | $ / shares	$ 148.61
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term of ending balance of options outstanding	6 years 3 months 18 days
Weighted average remaining contractual term of options fully vested	5 years 3 months 18 days
Weighted average remaining contractual term of options fully vested and expected to vest	6 years 3 months 18 days
Aggregate intrinsic value | $	$ 684,571
Aggregate intrinsic value of options fully vested | $	415,229
Aggregate intrinsic value of options expected to vest | $	$ 678,994