Transactions with Affiliates and Related Parties - Loans to Executive Officers, Directors and Affiliates (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes in loans executive officers, directors and affiliates
Balance at beginning of year	$ 94,466	$ 58,936	$ 95,494
New loans made	3,762	36,017	14,540
Repayments	(36,625)	(487)	(51,098)
Balance at end of year	$ 61,603	$ 94,466	$ 58,936