Benefit Plans (Details 3) (USD $)	0 Months Ended	12 Months Ended
	Dec. 20, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Incentive Savings Plan
Employee maximum contribution of pre-tax base salary, percentage		30.00%
Employee maximum contribution of pre-tax base salary limit		$ 17,500
Maximum percentage of the participating employees' contributions matched by the employer		50.00%
Maximum employer matching contribution as a percentage of participating employees' compensation		6.00%
Matching contributions		2,000,000	0	0
Employee vesting in employer contributions after period of time		1 year
Employee Stock Ownership Plan
ESOP loans outstanding principal balance			5,900,000
ESOP loans interest rate (as a percent)		6.00%
Shares allocated to participants	967,013		1,075,354	1,398,763
Shares allocated to participants to date		15,068,562
Remaining unallocated common stock held by ESOP		0	3,542,000
Cash contribution to participant accounts		155,000	513,000	1,800,000
Compensation expense related to ESOP		11,200,000	10,700,000	18,200,000
Contribution to be made to the plan subsequent to December 31, 2013		$ 0