Fair Value (Fair Value Measurements Using Significant Unobservable Inputs For Equity Index Put Option Contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value [Abstract]
Balance, beginning of period	$ 40,819	$ 33,309	$ 47,022	$ 35,423
Total (gains) or losses (realized/unrealized) Included in earnings	$ 11,428	$ (1,855)	$ 5,225	$ (3,968)
Total (gains) or losses (realized/unrealized) Included in other comprehensive income (loss)
Purchases, issuances and settlements
Transfers in and/or (out) of Level 3
Balance, end of period	$ 52,247	$ 31,455	$ 52,247	$ 31,455
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to liabilities still held at the reporting date