Debt (Grouping Of Debt Between Fixed And Variable As Well As Secured And Unsecured) (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Schedule of Long-term Debt, By Type [Line Items]
Total	[1]	$ 2,320,847	$ 2,113,277
As To Interest Rate [Member]
Schedule of Long-term Debt, By Type [Line Items]
Fixed-rate debt		2,169,019	1,869,683
Variable-rate debt		151,828	243,594
Total		2,320,847	2,113,277
As To Collateralization [Member]
Schedule of Long-term Debt, By Type [Line Items]
Unsecured debt		1,875,644	1,650,521
Secured debt		445,203	462,756
Total		$ 2,320,847	$ 2,113,277

[1] * Consolidated variable interest entities' assets and debt included in the above balances (see Note 15):