Noncontrolling Interests (Summary Of Changes In Controlling And Non-controlling Stockholders’ Equity) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Noncontrolling Interest [Line Items]
Balance				$ 181,241
Net income	$ 5,101	$ 19,052	[1]	8,169	$ 22,095	[1]
Distributions to noncontrolling stockholders				(93)	(133)
Accumulated other comprehensive income (loss)	7			10	(13)	[1]
Balance	181,168			181,168
Controlling Stockholders' Equity [Member]
Noncontrolling Interest [Line Items]
Balance				176,910	142,197
Adjustments to opening retained earnings on adoption of ASC 606	194			194
Net income				8,045	22,063
Increase in additional paid in capital				670	610
Treasury stock purchased				(397)	(3,400)
Contributions from noncontrolling stockholders
Distributions to noncontrolling stockholders
Sale of noncontrolling interest
Accumulated other comprehensive income (loss)				(8,659)	8,489
Balance	176,763	169,959		176,763	169,959
Noncontrolling Stockholders' Equity [Member]
Noncontrolling Interest [Line Items]
Balance				4,331	4,418
Adjustments to opening retained earnings on adoption of ASC 606	(2)			(2)
Net income				124	32
Increase in additional paid in capital
Treasury stock purchased
Contributions from noncontrolling stockholders				55	49
Distributions to noncontrolling stockholders				(93)	(131)
Sale of noncontrolling interest
Accumulated other comprehensive income (loss)				(10)	13
Balance	4,405	4,381		4,405	4,381
Total Stockholders' Equity [Member]
Noncontrolling Interest [Line Items]
Balance				181,241	146,615
Adjustments to opening retained earnings on adoption of ASC 606	192			192
Net income				8,169	22,095
Increase in additional paid in capital				670	610
Treasury stock purchased				(397)	(3,400)
Contributions from noncontrolling stockholders				55	49
Distributions to noncontrolling stockholders				(93)	(131)
Accumulated other comprehensive income (loss)				(8,669)	8,502
Balance	$ 181,168	$ 174,340		$ 181,168	$ 174,340

[1] Certain prior year balances have been reclassified to conform to the 2018 presentation (see Note 2 - Summary of Significant Accounting Policies - Reclassifications).