Employee Stock Benefit Plans (401(k) Plan Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Defined Contribution Plans Disclosures [Line Items]
Annual limit on eligible earnings imposed by Internal Revenue Code	$ 255,000
Total matching contribution to all Plans	3,100,000	2,300,000	2,400,000
Salary Plan
Schedule of Defined Contribution Plans Disclosures [Line Items]
Minimum annual contribution per participating employee, percent	1.00%
Maximum annual contribution per employee, percent	50.00%
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent	6.00%
Maximum annual employer matching contributions per employee, percent of employee gross pay		3.50%
Maximum annual employer matching contributions per employee	15,300
Salary Plan | First Portion
Schedule of Defined Contribution Plans Disclosures [Line Items]
Employer matching contribution, percent of match		100.00%
Employer matching contribution, percent		1.00%
Salary Plan | Remaining Portion
Schedule of Defined Contribution Plans Disclosures [Line Items]
Employer matching contribution, percent of match		50.00%
Employer matching contribution, percent		5.00%
Hourly Plan
Schedule of Defined Contribution Plans Disclosures [Line Items]
Minimum annual contribution per participating employee, percent	1.00%
Maximum annual contribution per employee, percent	25.00%
Maximum annual employer matching contributions per employee	$ 7,650
Hourly Plan | First Portion
Schedule of Defined Contribution Plans Disclosures [Line Items]
Employer matching contribution, percent of match	50.00%
Employer matching contribution, percent	6.00%