Employee Benefit Plans (Defined Benefit Plans Disclosure) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,158	$ 3,106	$ 9,465	$ 9,330
Interest cost	1,662	1,341	4,979	4,028
Expected return on plan assets	(1,788)	(1,884)	(5,364)	(5,651)
Amortization of prior service cost	61	82	182	247
Amortization of prior actuarial loss	1,073	929	3,215	2,792
Total	4,166	3,574	12,477	10,746
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	461	999	1,975	2,271
Interest cost	827	680	1,986	1,739
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(328)	(328)	(986)	(986)
Amortization of prior actuarial loss	29	937	1,317	1,933
Total	$ 989	$ 2,288	$ 4,292	$ 4,957