Employee Savings and Investment Plan (Additional Information) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
IRS deferral limit	$ 17,500	$ 17,000
Defined Contribution Plan, Employer Matching Contribution, Percent		6.00%
Defined Contribution Plan, Maximum Annual Contribution Per Employee, Percent		3.50%
Employer contributions		$ 1,700,000	$ 1,700,000	$ 1,500,000
100% match [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent		100.00%
1% of compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent		1.00%
50% match [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent		50.00%
5% of compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent		5.00%