Employee Benefit Plans Textual (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected 2014 amortization of pension prior service costs		insignificant
Effect of one percentage point increase on accumulated postretirement benefit obligation		$ 47
Effect of one percentage point decrease on accumulated postretirement benefit obligation		$ 44
Other Postretirement Benefit Plan [Member] | Minimum
Defined Benefit Plan Disclosure [Line Items]
Medical postretirement plans, qualifying retirement age range		62 years
Other Postretirement Benefit Plan [Member] | Maximum
Defined Benefit Plan Disclosure [Line Items]
Medical postretirement plans, qualifying retirement age range		65 years
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)		$ 199
Expected 2014 amortization of actuarial loss		947
Projected benefit obligation, pension plans with accumulated benefit obligations in excess of plan assets		5,467	$ 62,953
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation		5,467	62,302
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets		$ 0	$ 46,096
Pension Plans, Defined Benefit | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Company's Pension Plan Asset Allocation, Description		entirely	Entirely
Defined Benefit Plan, Target Plan Asset Allocations		100.00%
Pension Plans, Defined Benefit | Corporate Bond Securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Fixed Income Securities Allocations		87.00%	96.00%
Pension Plans, Defined Benefit | US Treasury and Government
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Fixed Income Securities Allocations		4.00%
Pension Plans, Defined Benefit | Agency Securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Fixed Income Securities Allocations		2.00%	2.00%
Pension Plans, Defined Benefit | Other fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Actual Fixed Income Securities Allocations		7.00%	2.00%
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, allowable matching percentage based on terms of the plan	100.00%
Employer matching contribution, percent		6.00%
Defined Contribution Plan, Cost Recognized		$ 2,725	$ 3,386	$ 3,296
One-time Termination Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plans,Withdrawal Obligation Expense		(1,973)	5,500
Multiemployer Plans, Withdrawal Obligation		$ 3,527	$ 5,500