Stock Based Compensation (Summary Of Company's Outstanding Restricted Stock Units) (Details) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares outstanding, Number of Shares, Beginning Balance | shares	978,028
Grants, Number of Shares | shares	366,200
Vests, Number of Shares | shares	(557,402)
Forfeitures, Number of Shares | shares	(38,007)
Shares outstanding, Number of Shares, Ending Balance | shares	748,819
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant-date fair value, shares outstanding, beginning balance (in dollars per share) | $ / shares	$ 51.39
Grants, weight-average grant-date fair value (in dollars per share) | $ / shares	63.09
Vests, weighted-average grant-date fair value (in dollars per share) | $ / shares	47.92
Forfeitures, weighted-average grant-date fair value (in dollars per share) | $ / shares	59.63
Weighted-average grant-date fair value, shares outstanding, ending balance (in dollars per share) | $ / shares	$ 59.34