Balance Sheet Components (Schedule Of Goodwill By Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill (period start)	$ 81,721	$ 81,721
Goodwill, Acquired During Period	3,742
Goodwill impairment charges	0	0	$ 74,196
Goodwill (period end)	85,463	81,721	81,721
Retail [Member]
Goodwill [Roll Forward]
Goodwill (period start)	45,442	45,442
Goodwill, Acquired During Period	3,742
Goodwill impairment charges		0
Goodwill (period end)	49,184	45,442	45,442
Commercial [Member]
Goodwill [Roll Forward]
Goodwill (period start)	36,279	36,279
Goodwill, Acquired During Period	0
Goodwill impairment charges		0
Goodwill (period end)	36,279	36,279	36,279
Service Provider [Member]
Goodwill [Roll Forward]
Goodwill (period start)	0	0
Goodwill, Acquired During Period	0
Goodwill impairment charges		0	74,196
Goodwill (period end)	$ 0	$ 0	$ 0