Payment Plan Receivables and Other Assets Held for Sale (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	May 01, 2017	Dec. 31, 2016
Payment Plan Receivables And Other Assets Held For Sale [Line Items]
Cash proceeds from sale of assets	$ 33,446	$ 0
Assets sold [Abstract]
Commercial loans	828,778			$ 804,017
Mepco [Member]
Payment Plan Receivables And Other Assets Held For Sale [Line Items]
Cash proceeds from sale of assets	33,400
Gain (loss) on sale of assets	$ 0
Assets sold [Abstract]
Payment plan receivables			$ 33,128	30,582
Commercial loans			525	794
Other assets			1,765	1,984
Total assets			35,418	33,360
Liabilities assumed			$ 1,972	$ 718