Compensation Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
LTIP Expense	$ 23,011,000	$ 14,170,000	$ 11,105,000
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	38,000,000	34,000,000	31,000,000
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	175,100
Long-Term Incentive Compensation Plan, Maximum Value	43,800,000
Long-Term Incentive Compensation Plan, Earned	27,300,000
LTIP Expense	9,855,000	6,939,000	6,822,000
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	0	4,283,000
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	208,000
Long-Term Incentive Compensation Plan, Maximum Value	52,000,000
Long-Term Incentive Compensation Plan, Earned	16,700,000
LTIP Expense	9,493,000	7,231,000	0
Long-term Incentive Compensation Plan, 2014 [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Long-Term Incentive Compensation Plan, Number of Units Oustanding	220,000
Long-Term Incentive Compensation Plan, Maximum Value	22,000,000
Long-Term Incentive Compensation Plan, Earned	3,700,000
LTIP Expense	$ 3,663,000	$ 0	$ 0