Stock-Based Compensation (Options) (Details) - Stock Options [Member] $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Number of Shares
Options outstanding, beginning balance (in shares) | shares	1,504
Options exercised (in shares) | shares	(215)
Options outstanding, ending balance (in shares) | shares	1,289
Weighted-Average Exercise Price
Options outstanding, beginning balance (usd per share) | $ / shares	$ 21.22
Options exercised (usd per share) | $ / shares	24.69
Options outstanding, ending balance (usd per share) | $ / shares	$ 20.64
Aggregate Intrinsic Value
Options outstanding, Aggregate Intrinsic Value | $	$ 32,985
Weighted Average Remaining Contractual Term
Options outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 4 months 26 days