Common Stock (Schedule of Stock Option Activity) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Shares
Outstanding at beginning of period (in shares) | shares	463
Granted (in shares) | shares	0
Exercised (shares) | shares	(425)
Canceled (in shares) | shares	(1)
Outstanding at end of period (in shares) | shares	37
Exercisable (in shares) | shares	31
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 27.47
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	25.51
Canceled (in dollars per share) | $ / shares	22.25
Outstanding at end of period (in dollars per share) | $ / shares	50.40
Exercisable (in dollars per share) | $ / shares	$ 44.85