Saving and Retirement Plans - 401(K) Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Amount	$ 5,000
Current Fiscal Year End Date	--12-31
Profit Sharing Contribution, Vesting Period	3 years
Profit Sharing Contributions, Cost Recognized	1,300,000	1,200,000	1,100,000
Defined Contribution Plan, Cost Recognized	$ 1,500,000	$ 1,500,000	$ 1,400,000