Stock-Based Compensation Plan (Summary Of Stock Option Plan Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Options Activity [Roll Forward]
Options outstanding at beginning of period (in shares)	1,263,485			1,192,680
Options outstanding at end of period (in shares)	1,420,749		1,335,680	1,192,680
Options exercisable at end of period (in shares)	1,169,312
Expected to vest after end of period (in shares)	251,437
Weighted Average Exercise Price [Roll Forward]
Options outstanding at beginning of period (in dollars per share)	$ 14.84			$ 12.89
Options outstanding at end of period (in dollars per share)	$ 15.67		$ 13.41	$ 12.89
Options exercisable at end of period (in dollars per share)	$ 14.28
Expected to vest after end of period (in dollars per share)	$ 22.16
Weighted Average Remaining Contractual Term [Abstract]
Options outstanding at end of period (in years)	5 years 4 months 24 days
Options exercisable at end of period (in years)	4 years 7 months 6 days
Expected to vest after end of period (in years)	8 years 10 months 24 days
Aggregate Intrinsic Value [Abstract]
Options outstanding at end of period	$ 11,270
Options exercisable at end of period	10,887
Expected to vest after end of period	$ 382
Employees [Member]
Stock Options Activity [Roll Forward]
Options granted - directors and employees (in shares)	120,000	51,300	111,000
Options forfeited - employees (in shares)	(5,417)	(3,501)
Options exercised - employees (in shares)	(7,319)	(159,994)
Weighted Average Exercise Price [Roll Forward]
Options granted - directors and employees (in dollars per share)	$ 22.09	$ 26.41	$ 17.77
Options forfeited - employees (in dollars per share)	$ 22.55	$ 14.87
Options exercised - employees (in dollars per share)	$ 15.60	$ 9.53
Directors [Member]
Stock Options Activity [Roll Forward]
Options granted - directors and employees (in shares)	50,000	40,000	40,000
Options forfeited - employees (in shares)			(8,000)
Weighted Average Exercise Price [Roll Forward]
Options granted - directors and employees (in dollars per share)	$ 22.09	$ 26.41	$ 17.77
Options forfeited - employees (in dollars per share)			$ 17.77