Debt Debt (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Debt Issuance Cost	15,018
Ten-Year Medium Term Notes
Debt Instrument [Line Items]
Long-term Debt Issued		500,000
Debt Instrument Maturity Period	2024-11
Interest Rate		3.30%
Twenty-Year Medium Term Notes
Debt Instrument [Line Items]
Long-term Debt Issued		500,000
Debt Instrument Maturity Period	2034-11
Interest Rate		4.20%
Thirty-Year Medium Term Notes
Debt Instrument [Line Items]
Long-term Debt Issued		$ 500,000
Debt Instrument Maturity Period	2044-11
Interest Rate		4.45%