Share-Based Compensation (RSU Activity During the Year) (Details) (Restricted Stock Units (RSUs) [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock Units (RSUs) [Member]
Outstanding and unvested, beginning balance, in shares	1,340,982	1,284,692	1,307,173
RSUs, granted, in shares	378,873	685,441	643,822
RSUs, vested, in shares	(630,185)	(669,079)	(575,214)
RSUs, cancelled, in shares	(41,921)	(63,954)	(91,089)
Outstanding and unvested, ending balance, in shares	1,047,749	1,340,982	1,284,692
Weighted average grant date fair value, beginning of Period, in dollars per share	$ 38.49	$ 39.81	$ 35.00
Weighted average grant date fair value, granted, in dollars per share	$ 59.79	$ 53.78	$ 40.74
Weighted average grant date fair value, vested, in dollars per share	$ 35.73	$ 38.44	$ 30.05
Weighted average grant date fair value, cancelled, in dollars per share	$ 45.14	$ 43.98	$ 38.92
Weighted average grant date fair value, end of Period, in dollars per share	$ 47.60	$ 38.49	$ 39.81