Retirement Plans - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
401K Plan [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred Compensation Arrangement with Individual, Employer Contribution	$ 2,609,000
Profit Sharing [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred Compensation Arrangement with Individual, Employer Contribution		1,678,000	1,355,000
Executive Officer [Member] | SERP [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Plan expense recognized	477,000	784,000	459,000
Discount rate for benefit obligations	3.75%
Accrued compensation	$ 4,500,000	$ 4,500,000