Employee Benefit Plans (Schedule Of Stock Option Activity) (Details) - Stock Options [Member] $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares, Beginning Balance (in shares) | shares	1,884
Number of Shares, Granted (in shares) | shares	348
Number of Shares, Exercised (in shares) | shares	(352)
Number of Shares, Expired (in shares) | shares	(1)
Number of Shares, Ending Balance (in shares) | shares	1,879
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Beginning Balance (in dollars per share) | $ / shares	$ 31.14
Grants (in dollars per share) | $ / shares	43.07
Exercises (in dollars per share) | $ / shares	27.23
Expired (in dollars per share) | $ / shares	31.70
Ending Balance (in dollars per share) | $ / shares	$ 34.08
Outstanding, Weighted Average Remaining Contractual Term	6 years 1 month 18 days
Outstanding, Intrinsic Value | $	$ 46,346
Vested and Expected to Vest, Number | shares	1,879
Vested and Expected to Vest, Weighted Average Exercise Price | $ / shares	$ 34.08
Vested and Expected to Vest, Weighted Average Remaining Contractual Term	6 years 1 month 18 days
Vested and Expected to Vest, Aggregate Intrinsic Value | $	$ 46,346
Exercisable, Number | shares	1,205
Exercisable, Weighted Average Exercise Price | $ / shares	$ 30.94
Exercisable, Weighted Average Remaining Contractual Term	4 years 8 months 18 days
Exercisable, Intrinsic Value | $	$ 33,512