Stock-Based Compensation (Stock Option Activity) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Number of options (in shares):
Options outstanding beginning of the year (in shares) | shares	262,282
Exercised (in shares) | shares	(90,765)
Options outstanding end of the year (in shares) | shares	171,517
Weighted Average Exercise Price (in dollars per share):
Options outstanding beginning of the year (in dollars per share) | $ / shares	$ 42.52
Exercised (in dollars per share) | $ / shares	44.29
Options outstanding end of the year (in dollars per share) | $ / shares	$ 41.59
Outstanding, Intrinsic Value | $	$ 9