Summary Of Significant Accounting Policies (Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Rollforward of Redeemable Noncontrolling Interests
Beginning balance	$ 137,316	$ 119,053
Net income	2,713	3,423	$ 3,452
Distributions & Redemptions	(16,426)	(4,286)
Contributions	0	12
Change in redemption value	20,091	19,114
Ending balance	143,694	137,316	119,053
Redeemable Noncontrolling Interest [Line Items]
Redemption of redeemable noncontrolling interests	$ 13,018	$ 0	$ 0