Property Held For Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Activity of Property Held for Sale [Roll Forward]
Beginning balance	$ 24,504	$ 25,567	$ 37,529
Acquisitions	363	2,356	2,617
Real Estate Acquired Through Foreclosure Acquired through Merger Acquisition	2,377	23
Capitalized improvements	316	463	39
Dispositions	(5,205)	(3,237)	(12,203)
Valuation adjustments	(885)	(668)	(2,415)
Balance at year end	$ 21,470	$ 24,504	$ 25,567