Equity And Stock-Based Compensation (Schedule Of Stock Options Outstanding And Exercisable) (Details) - $ / shares shares in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Equity And Stock-Based Compensation [Line Items]
Weighted Average Exercise Price of Options Outstanding, Granted	$ 11.83	$ 12.34
Weighted average remaining years of contractual life	3 years 2 months 1 day		2 years 10 months 21 days	2 years 4 months 24 days
Weighted average remaining contractual life of the exercisable options outstanding	2 years 15 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	142		112
Common Stock Options Outstanding, Exercised			(185)
Common Stock Options Outstanding, Forfeited	(2)		(8)
Common Stock Options Outstanding, Ending balance	627		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	11.83		13.30
Weighted Average Exercise Price of Options Outstanding, Exercised			6.09
Weighted Average Exercise Price of Options Outstanding, Forfeited	6.23		6.23
Weighted Average Exercise Price of Options Outstanding, Ending price	$ 9.40		$ 7.64	$ 6.88
Common Stock Exercisable Options, Outstanding Beginning balance	256	348	348
Common Stock Exercisable Options Outstanding, Granted	10		101
Common Stock Exercisable Options Outstanding, Exercised			(185)
Common Stock Exercisable Options Outstanding, Forfeited			(8)
Common Stock Exercisable Options, Outstanding Ending balance	266		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	$ 7.78		$ 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, Exercised			(185)
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, Exercised			$ 9.90
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, Exercised			(185)
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