Employee Benefit Plans (Defined Benefit Plans Disclosure) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,479	$ 2,307	$ 7,437	$ 6,923
Interest cost	1,168	1,262	3,503	3,788
Expected return on plan assets	(1,285)	(1,224)	(3,854)	(3,673)
Amortization of prior service cost	76	82	229	245
Amortization of prior actuarial loss	1,040	636	3,121	1,908
Total	3,478	3,063	10,436	9,191
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	131	1,868	2,162	3,046
Interest cost	408	947	1,694	1,929
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(467)	0	(467)	0
Amortization of prior actuarial loss	137	1,319	1,370	1,849
Total	$ 209	$ 4,134	$ 4,759	$ 6,824