Debt (Grouping Of Debt Between Fixed And Variable As Well As Secured And Unsecured) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Schedule of Long-term Debt, By Type [Line Items]
Secured debt (1)		$ 66,000
Total	[1]	2,113,277	$ 1,930,009
As To Interest Rate [Member]
Schedule of Long-term Debt, By Type [Line Items]
Fixed-rate debt (1)		1,869,683	1,643,780
Variable-rate debt		243,594	286,229
Total		2,113,277	1,930,009
As To Collateralization [Member]
Schedule of Long-term Debt, By Type [Line Items]
Unsecured debt (1)		1,650,521	1,337,191
Secured debt (1)		462,756	592,818
Total		$ 2,113,277	$ 1,930,009

[1] Consolidated variable interest entities' assets held as collateral and debt included in the above balances (see Note 21):