Compensation Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Period of Measurement for Book Value Per Share	5 years
LTIP Expense	$ 14,127,000	$ 13,107,000	$ 10,220,000
Deferred Profit Sharing
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Profit Sharing Plan Minimum Contribution, Percent	5.00%
Profit Sharing Plan, Contributions Vesting Immediately, Percent	40.00%
Profit Sharing Plan, Contributions Vesting Based on Years of Service, Percent	60.00%
Profit sharing expense	34,000,000	31,000,000	27,000,000
2011 grant
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Long-Term Incentive Compensation Plan, Number of Units Oustanding	183,100
Long-Term Incentive Compensation Plan, Maximum Value	45,800,000
Long-Term Incentive Compensation Plan, Earned	19,700,000
LTIP Expense	6,741,000	7,365,000	5,620,000
2008 grant
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Long-Term Incentive Compensation Plan, Earned	23,000,000
LTIP Expense	0	5,742,000	4,600,000
Number Of Years Long Term Compensation Was Earned		5 years
2013 grant
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Long-Term Incentive Compensation Plan, Number of Units Oustanding	211,250
Long-Term Incentive Compensation Plan, Maximum Value	52,800,000
Long-Term Incentive Compensation Plan, Earned	7,400,000
LTIP Expense	$ 7,386,000	$ 0	$ 0