Post-retirement Plans (Net Periodic Pension Expense) (Details) - USD ($) $ in Thousands	11 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 1,648	$ 1,511	$ 1,294
Interest cost		938	987	787
Amortization of Prior Service Cost (Credit)		(3,481)	(3,481)	(3,482)
Net periodic post-retirement credit		(895)	$ (983)	$ (1,401)
Business Combination Acquiree [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,598	4,420
Interest cost	1,979	2,249
Expected return on plans assets	(2,841)	(3,464)
Net periodic pension expense	$ 2,736	$ 3,205