Share-Based Payments (Summary of the Status of the Company's Employee Stock Option Grants) (Details) - Employee stock options	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Shares
Outstanding (in shares) | shares	4,584,244
Granted (in shares) | shares	569,137
Exercised (in shares) | shares	(541,473)
Forfeited (in shares) | shares	(165)
Expired (in shares) | shares	(746)
Outstanding (in shares) | shares	4,610,997
Exercisable (in shares) | shares	3,614,679
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 72.03
Granted (in dollars per share) | $ / shares	93.36
Exercised (in dollars per share) | $ / shares	58.56
Forfeited (in dollars per share) | $ / shares	76.71
Expired (in dollars per share) | $ / shares	19.86
Outstanding (in dollars per share) | $ / shares	76.26
Exercisable (in dollars per share) | $ / shares	$ 70.03
Assurance IQ
Shares
Outstanding (in shares) | shares	0
Granted (in shares) | shares	584,017
Exercised (in shares) | shares	(36,825)
Forfeited (in shares) | shares	0
Expired (in shares) | shares	0
Outstanding (in shares) | shares	547,192
Exercisable (in shares) | shares	33,596
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 0.00
Granted (in dollars per share) | $ / shares	1.36
Exercised (in dollars per share) | $ / shares	0.98
Forfeited (in dollars per share) | $ / shares	0.00
Expired (in dollars per share) | $ / shares	0.00
Outstanding (in dollars per share) | $ / shares	1.38
Exercisable (in dollars per share) | $ / shares	$ 2.08