Fair Value Measurements (Financial instruments level within the fair value hierarchy) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Jun. 30, 2014
Assets:
Short-term investments	$ 391,113	$ 460,762
Fixed maturities - available for sale	1,290,830	1,262,012
Preferred stock	18,552	18,296
Common stock	24,817	24,654
Derivatives	4,351	4,876
Total	$ 1,729,663	$ 1,770,600
Liabilities:
Guaranteed residual values of TRAC leases
Derivatives	$ 21,121	$ 24,484
Total	21,121	24,484
Level 1 [Member]
Assets:
Short-term investments	391,113	460,762
Fixed maturities - available for sale	1,007,559	967,986
Preferred stock	18,552	18,296
Common stock	24,817	24,654
Derivatives	4,351	4,876
Total	$ 1,446,392	$ 1,476,574
Liabilities:
Guaranteed residual values of TRAC leases
Derivatives
Total
Level 2 [Member]
Assets:
Short-term investments
Fixed maturities - available for sale	$ 282,315	$ 293,022
Preferred stock
Common stock
Derivatives
Total	$ 282,315	$ 293,022
Liabilities:
Guaranteed residual values of TRAC leases
Derivatives	$ 21,121	$ 24,484
Total	$ 21,121	$ 24,484
Level 3 [Member]
Assets:
Short-term investments
Fixed maturities - available for sale	$ 956	$ 1,004
Preferred stock
Common stock
Derivatives
Total	$ 956	$ 1,004
Liabilities:
Guaranteed residual values of TRAC leases
Derivatives
Total