Profit Sharing Plan (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions and earnings, vesting schedule	5 years
Employer matching contributions, vesting period of service	$ 4.0	$ 3.4	$ 3.5
Profit Sharing Plan
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions and earnings, vesting schedule	5 years