Employee Benefit Plans (Details) - USD ($)	1 Months Ended	2 Months Ended
	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		4.10%		3.80%
Net Periodic Benefit Cost [Abstract]
Defined Benefit Plans Impact of Plan Re-measurement		$ (9,700,000)
Defined Benefit Plan, Amounts Recognized in Balance Sheet		$ (11,700,000)
Plan 401 K | Other Postretirement Benefit Plan
Defined Contribution Plan Disclosure [Line Items]
Plan Vesting Period Defined Contribution Plan		6 months
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		5.00%
Employer Contribution to Plan		$ 1,300,000	$ 1,300,000
Money Purchase Pension Plan | Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Plan Vesting Period Defined Contribution Plan		3 years
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		4.00%
Employer Contribution Percentage Above IRS Limit		4.00%
Pension Contributions		$ 0	0
Money Purchase Pension Plan | Pension Plan | Subsequent Event
Defined Contribution Plan Disclosure [Line Items]
Pension Contributions	$ 2,200,000
Defined Contribution Restoration Plan | Other Postretirement Benefit Plan
Defined Contribution Plan Disclosure [Line Items]
Employer Contribution to Plan - deferred compensation		400,000	500,000
Qualified Pension
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		11,000,000
Employer contributions		10,000,000	10,000,000
Net Periodic Benefit Cost [Abstract]
Service cost		2,000,000	1,800,000
Interest cost		2,100,000	1,600,000
Expected return on plan assets		(3,800,000)	(4,000,000)
Amortization of prior service cost (credit)		(400,000)	(300,000)
Amortization of net loss		1,900,000	1,400,000
Settlement loss recognized		2,500,000	0
Other		100,000	0
Net periodic benefit cost		4,400,000	500,000
Non Qualified Pension
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		500,000
Employer contributions		100,000	100,000
Net Periodic Benefit Cost [Abstract]
Service cost		0	0
Interest cost		0	0
Expected return on plan assets		0	0
Amortization of prior service cost (credit)		0	100,000
Amortization of net loss		0	0
Settlement loss recognized		0	0
Other		0	0
Net periodic benefit cost		0	100,000
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		2,200,000
Net Periodic Benefit Cost [Abstract]
Service cost		200,000	200,000
Interest cost		200,000	200,000
Expected return on plan assets		(300,000)	(300,000)
Amortization of prior service cost (credit)		0	(100,000)
Amortization of net loss		100,000	100,000
Settlement loss recognized		0	0
Other		0	0
Net periodic benefit cost		$ 200,000	$ 100,000