Share-Based Payments (Summary of the Status of the Company's Employee Stock Option Grants) (Details) - Employee stock options	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Shares
Outstanding (in shares) | shares	4,610,997
Granted (in shares) | shares	610,027
Exercised (in shares) | shares	(647,313)
Forfeited (in shares) | shares	0
Expired (in shares) | shares	(9,859)
Outstanding (in shares) | shares	4,563,852
Exercisable (in shares) | shares	3,427,197
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 76.26
Granted (in dollars per share) | $ / shares	95.87
Exercised (in dollars per share) | $ / shares	59.82
Forfeited (in dollars per share) | $ / shares	0.00
Expired (in dollars per share) | $ / shares	78.45
Outstanding (in dollars per share) | $ / shares	81.21
Exercisable (in dollars per share) | $ / shares	$ 76.25
Assurance IQ
Shares
Outstanding (in shares) | shares	547,192
Granted (in shares) | shares	0
Exercised (in shares) | shares	(142,638)
Forfeited (in shares) | shares	(10,288)
Expired (in shares) | shares	0
Outstanding (in shares) | shares	394,266
Exercisable (in shares) | shares	57,791
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 1.38
Granted (in dollars per share) | $ / shares	0.00
Exercised (in dollars per share) | $ / shares	0.51
Forfeited (in dollars per share) | $ / shares	5.10
Expired (in dollars per share) | $ / shares	0.00
Outstanding (in dollars per share) | $ / shares	1.60
Exercisable (in dollars per share) | $ / shares	$ 4.02