Employee Benefit Costs (Schedule of Projected Benefit Payments) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013
Qualified [Member] | Pension Benefits [Member]
2014	$ 74,800
2015	75,123
2016	75,155
2017	75,138
2018	75,065
2019-2023	371,195
Non-Qualified [Member] | Pension Benefits [Member]
2014	3,165
2015	3,239
2016	3,282
2017	3,338
2018	3,380
2019-2023	18,460
Retiree Medical [Member] | Other Postretirement Benefits [Member]
2014	14,516
2015	13,604
2016	12,720
2017	10,679
2018	9,714
2019-2023	28,670
Retiree Life [Member] | Other Postretirement Benefits [Member]
2014	1,425
2015	1,452
2016	1,476
2017	1,496
2018	1,512
2019-2023	7,682
LTD [Member] | Other Postretirement Benefits [Member]
2014	155
2015	149
2016	145
2017	133
2018	118
2019-2023	$ 431