Accounting for Stock-Based Compensation (Schedule of Share-based Compensation, Restricted Stock, Activity) (Details) (Restricted Stock [Member], USD $)	3 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Unvested Shares	1,605,774	1,617,182	1,744,564
Granted, Shares	37,500		786,588
Vested, Shares	(10,756)	(7,053)	(913,970)
Forfeited, Shares	(3,689)	(4,355)
Ending Balance, Unvested Shares	1,628,829	1,605,774	1,617,182
Beginning of Period, Weighted Average Grant Date Fair Value	$ 34.81	$ 34.79	$ 30.50
Granted, Weighted Average Grant Date Fair Value	$ 43.44		$ 41.49
Vested, Weighted Average Grant Date Fair Value	$ 28.24	$ 28.52	$ 32.38
Forfeited, Weighted Average Grant Date Fair Value	$ 34.86	$ 34.47
End of Period, Weighted Average Grant Date Fair Value	$ 35.06	$ 34.81	$ 34.79