Goodwill and Other Intangible Assets (Goodwill And Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Finite-lived Intangible Assets [Roll Forward]
Other intangible assets, gross	$ 113,471		$ 113,471	$ 113,471
Other intangible assets, accumulated amortization	(78,274)		(76,585)	(67,963)
Other intangible assets, net	35,197		36,886	$ 45,508
Other intangible assets, amortization	$ (1,689)	$ (2,560)	$ (8,622)