Share-Based Compensation and Benefit Plans (Nonqualified Deferred Compensation Plan) (Narrative) (Details) - Nonqualified Deferred Compensation Plan [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Share-Based Compensation and Benefit Plans
Deferred compensation plan description			The Company sponsors a nonqualified deferred compensation plan (the "Deferred Compensation Plan") for highly compensated employees whose contributions to the 401(k) Plan are limited due to the application of the annual limitations under the Internal Revenue Code. The Deferred Compensation Plan provides these employees with the opportunity to defer compensation that was precluded under the Company's 401(k) Plan due to the annual limitations, including salary and incentive based compensation, which is then matched by the Company using the same formula as the 401(k) Plan.
Deferred compensation plan obligation	$ 17.0		$ 17.0		$ 15.4
Deferred compensation plan cost recognized	$ 0.1	$ 0.1	$ 0.1	$ 0.1