Stock-Based Compensation and Other Employee Benefit Plans (Schedule of Activity, Employee Stock Purchase Plans) (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Common shares issued (in shares)	57,258	62,102
Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Cash proceeds (in dollars)	$ 0.9	$ 1.7
Employee Stock Purchase Plans [Member] | Common Stock [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Weighted average price per share (in dollars per share)	$ 16.41	$ 26.90
Weighted average per share grant date fair value (in dollars per share)	$ 4.43	$ 6.39