Fair Value (Details) - Rollforward of Carrying Value of CDOs $ in Thousands		12 Months Ended
		Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) security
Rollforward of the Carrying Value of CDOs
Carrying Value Of CDOs Sold	[1]	$ 0	$ 171	$ 8,934
CDOs
Rollforward of the Carrying Value of CDOs
Beginning balance		31,529	33,774	18,309
Additions		0	0	6,549
Change in other comprehensive (loss) income	[2]	2,337	(2,030)	13,495
Paydowns and sales	[3]	(606)	(215)	(4,579)
Ending balance		$ 33,260	$ 31,529	$ 33,774
Number Of CDOs Sold | security				1
Carrying Value Of CDOs Sold				$ 1,300
Great Lakes Financial Resources, Inc. | CDOs
Rollforward of the Carrying Value of CDOs
Number Of CDOs Sold | security				4
Securities available-for-sale				$ 2,900

[1] These reductions were driven by the sale of one CMO with a carrying value of $1.3 million during the year ended December 31, 2015 and one CDO with a carrying value of $1.3 million and one municipal security with a carrying value of $357,000 during the year ended December 31, 2014

[2] Included in unrealized holding (losses) gains in the Consolidated Statements of Comprehensive Income.

[3] During the year ended December 31, 2014, one CDO with a carrying value of $1.3 million and four CDOs totaling $2.9 million, which were acquired in the Great Lakes transaction, were sold.