Equity And Stock-Based Compensation (Schedule Of Stock Options Outstanding And Exercisable) (Details) - $ / shares shares in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Equity And Stock-Based Compensation [Line Items]
Weighted Average Exercise Price of Options Outstanding, Granted	$ 11.87	$ 13.42
Weighted average remaining years of contractual life	2 years 11 months 27 days		2 years 10 months 21 days	2 years 4 months 24 days
Weighted average remaining contractual life of the exercisable options outstanding	1 year 11 months 19 days		2 years 1 month 21 days	3 years 7 months 17 days
Class A [Member]
Equity And Stock-Based Compensation [Line Items]
Common Stock Options Outstanding, Beginning balance	487	568	568
Common Stock Options Outstanding, Granted	169		112
Common Stock Options Outstanding, Exercised			(185)
Common Stock Options Outstanding, Forfeited	(24)		(8)
Common Stock Options Outstanding, Ending balance	632		487	568
Weighted Average Exercise Price of Options Outstanding, Beginning price	$ 7.64	$ 6.88	$ 6.88
Weighted Average Exercise Price of Options Outstanding, Granted	11.87		13.30
Weighted Average Exercise Price of Options Outstanding, Exercised			6.09
Weighted Average Exercise Price of Options Outstanding, Forfeited	8.49		6.23
Weighted Average Exercise Price of Options Outstanding, Ending price	$ 9.54		$ 7.64	$ 6.88
Common Stock Exercisable Options, Outstanding Beginning balance	256	348	348
Common Stock Exercisable Options Outstanding, Granted	61		101
Common Stock Exercisable Options Outstanding, Exercised			(185)
Common Stock Exercisable Options Outstanding, Forfeited	(2)		(8)
Common Stock Exercisable Options, Outstanding Ending balance	315		256	348
Weighted Average Price of Exercisable Options, Outstanding Beginning balance	$ 7.64	$ 6.82	$ 6.82
Weighted Average Price of Exercisable Options, Outstanding Ending balance	$ 8.12		$ 7.64	$ 6.82
Class B [Member]
Equity And Stock-Based Compensation [Line Items]
Common Stock Options Outstanding, Beginning balance		185	185
Common Stock Options Outstanding, Granted
Common Stock Options Outstanding, Exercised			(185)
Common Stock Options Outstanding, Forfeited
Common Stock Options Outstanding, Ending balance				185
Weighted Average Exercise Price of Options Outstanding, Beginning price		$ 9.90	$ 9.90
Weighted Average Exercise Price of Options Outstanding, Granted
Weighted Average Exercise Price of Options Outstanding, Exercised			9.90
Weighted Average Exercise Price of Options Outstanding, Forfeited
Weighted Average Exercise Price of Options Outstanding, Ending price				$ 9.90
Common Stock Exercisable Options, Outstanding Beginning balance		185	185
Common Stock Exercisable Options Outstanding, Granted
Common Stock Exercisable Options Outstanding, Exercised			(185)
Common Stock Exercisable Options Outstanding, Forfeited
Common Stock Exercisable Options, Outstanding Ending balance				185
Weighted Average Price of Exercisable Options, Outstanding Beginning balance		$ 9.90	$ 9.90
Weighted Average Price of Exercisable Options, Outstanding Ending balance				$ 9.90