Loans Receivable - Related Party Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance outstanding at beginning of year	$ 8,367,000	$ 8,460,000	$ 19,917,000
Elimination of outstanding loan balance due to change in related party status	0	0	10,930,000
Principal additions	0	211,000	0
Principal reductions	(223,000)	(304,000)	(527,000)
Balance outstanding at end of year	8,144,000	8,367,000	$ 8,460,000
Unfunded commitments to related parties	557,000,000	592,000,000
Borrowings from related parties	$ 0	$ 0