Employment Benefit Plans Postretirement Health Care and Other Benefits (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2013	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Unfunded Accumulated Postretirement Benefit Obligations Determined By Company			$ 10,427
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation			1,695
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components			169
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation			1,328
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components			$ 129
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			4.25%	4.00%
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months			$ 312
Defined Benefit Plan, Expected Future Benefit Payments, Year Two			319
Defined Benefit Plan, Expected Future Benefit Payments, Year Three			338
Defined Benefit Plan, Expected Future Benefit Payments, Year Four			358
Defined Benefit Plan, Expected Future Benefit Payments, Year Five			368
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter			2,276
Defined Benefit Plan, Benefit Obligation			$ 3,971
Maximum [Member]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year			6.00%
Minimum [Member]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year			4.50%
Successor [Member]
Postemployment Benefits, Period Expense		$ 2,101	$ 2,570	$ 2,249
Predecessor [Member]
Postemployment Benefits, Period Expense	$ 1,344