Share-Based Compensation and Benefit Plans Share-Based Compensation and Benefit Plans (Nonqualified Deferred Compensation Plan) (Narrative) (Details) (Deferred Compensation Plan [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Compensation Plan [Member]
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 the full 6% of compensation, including salary and incentive based compensation that would have been covered under the 401(k) Plan, which are then matched by the Company using the same formula as the 401(k) Plan.
Deferred compensation plan obligation	$ 15.4
Deferred compensation plan cost recognized	$ 0.2	$ 0.2	$ 0.1