Employee Benefits (Retirement Plans And Other Postretirement Benefits) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,173	$ 2,400	$ 9,100	$ 9,004
Interest cost	3,870	3,400	14,084	13,579
Expected return on plan assets	(4,680)	(4,275)	(17,513)	(15,108)
Amortization of prior service (benefit) cost	(259)	25	(187)	113
Amortization of net (gain) loss	1,773	2,675	10,196	11,066
Net periodic benefit cost (benefit)	2,877	4,225	15,680	18,654
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	700	1,100	3,443	4,408
Interest cost	1,125	1,375	4,906	5,611
Expected return on plan assets	(525)	(475)	(2,001)	(1,754)
Amortization of prior service (benefit) cost	(1,200)	(1,425)	(5,432)	(5,832)
Amortization of net (gain) loss	(650)	0	(1,276)	455
Net periodic benefit cost (benefit)	$ (550)	$ 575	$ (360)	$ 2,888