Payment Plan Receivables and Other Assets Held for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Payment Plan Receivables And Other Assets Held For Sale [Line Items]
Commercial loans	$ 815,484	$ 804,017
Mepco [Member]
Payment Plan Receivables And Other Assets Held For Sale [Line Items]
Payment plan receivables	32,300	30,600
Commercial loans	600	800
Other assets to be sold	1,900	2,000
Liabilities to be assumed	$ 1,400	$ 700