3. Amortized Cost and Fair Value of Debt Securities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014
Fair Value Disclosures [Abstract]
Mature in less than one year	$ 96.0
Mature in one to five years	110.5
Mature in more than five years	39.5
Total Amortized Cost	246.0
Mature in less than one year	96.1
Mature in one to five years	110.6
Mature in more than five years	39.4
Estimated Fair Value	$ 246.1