Business Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total interest income	$ 345,647	$ 356,592	$ 406,568
Interest expense	(41,475)	(57,165)	(69,196)
Net interest income	304,172	299,427	337,372
Provision for Loan and Lease Losses, net	(113,139)	(65,076)	(161,501)
Total non-interest income (loss), net	78,687	66,819	52,576
Non-interest expenses	(201,631)	(215,990)	(248,505)
Intersegment revenues	0	0	0
Intersegment expenses	0	0	0
Income (loss) before Income Taxes, Parent	68,089	85,180	(20,058)
Income Tax Expense (Benefit)	15,443	25,994	(17,554)
Net (Loss) Income Attributable to Parent	52,646	59,186	(2,504)
Total assets	6,189,053	6,501,824
Banking [Member]
Segment Reporting Information [Line Items]
Total interest income	311,503	321,868	367,620
Interest expense	(26,308)	(27,838)	(28,425)
Net interest income	285,195	294,030	339,195
Provision for Loan and Lease Losses, net	(113,108)	(65,076)	(161,501)
Total non-interest income (loss), net	45,102	35,587	24,004
Non-interest expenses	(178,540)	(193,156)	(219,519)
Intersegment revenues	1,604	1,521	1,427
Intersegment expenses	(748)	(883)	(948)
Income (loss) before Income Taxes, Parent	39,505	72,023	(17,342)
Total assets	5,597,077	5,584,866	5,867,874
Financial Services
Segment Reporting Information [Line Items]
Total interest income	53	65	95
Interest expense	0	0	0
Net interest income	53	65	95
Provision for Loan and Lease Losses, net	0	0	0
Total non-interest income (loss), net	26,069	26,788	28,288
Non-interest expenses	(17,830)	(17,443)	(22,564)
Intersegment revenues	0	0	0
Intersegment expenses	(1,137)	(1,108)	(1,027)
Income (loss) before Income Taxes, Parent	7,155	8,302	4,792
Total assets	25,980	23,315	22,349
Treasury [Member]
Segment Reporting Information [Line Items]
Total interest income	34,091	34,659	38,853
Interest expense	(15,167)	(29,327)	(40,771)
Net interest income	18,924	5,332	(1,918)
Provision for Loan and Lease Losses, net	(31)	0	0
Total non-interest income (loss), net	7,516	4,444	284
Non-interest expenses	(5,261)	(5,391)	(6,422)
Intersegment revenues	748	883	948
Intersegment expenses	(467)	(413)	(400)
Income (loss) before Income Taxes, Parent	21,429	4,855	(7,508)
Total assets	1,536,417	1,837,514	2,126,921
Major Segment [Member]
Segment Reporting Information [Line Items]
Total interest income	345,647	356,592	406,568
Interest expense	(41,475)	(57,165)	(69,196)
Net interest income	304,172	299,427	337,372
Provision for Loan and Lease Losses, net	(113,139)	(65,076)	(161,501)
Total non-interest income (loss), net	78,687	66,819	52,576
Non-interest expenses	(201,631)	(215,990)	(248,505)
Intersegment revenues	2,352	2,404	2,375
Intersegment expenses	(2,352)	(2,404)	(2,375)
Income (loss) before Income Taxes, Parent	68,089	85,180	(20,058)
Total assets	7,159,474	7,445,695	8,017,144
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Total interest income	0	0	0
Interest expense	0	0	0
Net interest income	0	0	0
Provision for Loan and Lease Losses, net	0	0	0
Total non-interest income (loss), net	0	0	0
Non-interest expenses	0	0	0
Intersegment revenues	(2,352)	(2,404)	(2,375)
Intersegment expenses	2,352	2,404	2,375
Income (loss) before Income Taxes, Parent	0	0	0
Total assets	(970,421)	(943,871)	(917,995)
Consolidated Total [Member]
Segment Reporting Information [Line Items]
Total interest income	345,647	356,592	406,568
Interest expense	(41,475)	(57,165)	(69,196)
Net interest income	304,172	299,427	337,372
Provision for Loan and Lease Losses, net	(113,139)	(65,076)	(161,501)
Total non-interest income (loss), net	78,687	66,819	52,576
Non-interest expenses	(201,631)	(215,990)	(248,505)
Intersegment revenues	0	0	0
Intersegment expenses	0	0	0
Income (loss) before Income Taxes, Parent	68,089	85,180	(20,058)
Total assets	$ 6,189,053	$ 6,501,824	$ 7,099,149