Stock-Based Compensation (Activity Pertaining To Restricted Stock Awards) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, beginning balance	589,527	447,961	446,125
Weighted average grant date price, beginning balance	$ 48.11	$ 47.44	$ 47.39
Number of shares, granted	453,549	376,445	211,050
Weighted average grant date price, granted	$ 48.20	$ 47.37	$ 55.91
Number of Shares, Vested	(248,003)	(220,788)	(190,262)
Weighted average grant date price, exercised	$ 46.46	$ 45.66	$ 43.32
Number of shares, forfeited	(18,330)	(14,091)	(18,952)
Weighted average grant date price, forfeited	$ 47.85	$ 45.37	$ 44.55
Number of shares, ending balance	776,743	589,527	447,961
Weighted average grant date price, ending balance	$ 48.70	$ 48.11	$ 47.44
Non-employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, beginning balance	24,606	0
Weighted average grant date price, beginning balance	$ 40.23	$ 0.00
Number of shares, granted	21,128	24,606
Weighted average grant date price, granted	$ 41.65	$ 40.23
Number of Shares, Vested	(10,030)	0
Weighted average grant date price, exercised	$ 40.23	$ 0.00
Number of shares, forfeited	0	0
Weighted average grant date price, forfeited	$ 0.00	$ 0.00
Number of shares, ending balance	35,704	24,606
Weighted average grant date price, ending balance	$ 41.07	$ 40.23