Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 315,628	$ 278,784	$ 221,717
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for credit losses	46,768	68,443	65,874
Depreciation and amortization	222,602	206,567	182,226
Impairment of goodwill and other intangible assets	0	73,409	0
Provision (benefit) for deferred income taxes	58,986	(53,729)	32,966
Proceeds from sales of loans and leases held for sale	372,354	280,640	1,044,282
Originations of loans and leases held for sale, net of repayments	(375,622)	(430,121)	(1,207,227)
Gains on sales of assets, net	(39,881)	(51,965)	(97,383)
Net change in other assets and accrued expenses and other liabilities	(2,121)	(96,380)	71,495
Other, net	(41,949)	(36,196)	(24,667)
Net cash provided by (used in) operating activities	556,765	239,452	289,283
Cash flows from investing activities:
Proceeds from sales of debt securities	254,146	0	0
Proceeds from maturities of and principal collected on debt securities	185,029	137,544	145,782
Purchases of debt securities	(1,232,618)	(354,608)	(692,996)
Redemption of Federal Home Loan Bank stock	269,002	246,002	156,967
Purchases of Federal Home Loan Bank stock	(278,000)	(254,000)	(161,080)
Proceeds from sales of loans and leases	903,606	1,618,791	2,830,807
Principal collected on loans and leases, net of loan and lease originations and purchases	172,849	(1,808,603)	(2,200,776)
Acquisition of Equipment Financing & Leasing Corporation, net of cash acquired	0	(8,120)	0
Purchases of lease equipment	(1,230,094)	(1,038,208)	(1,197,281)
Proceeds from sales of assets	88,942	63,875	76,885
Purchases of premises and equipment	(56,091)	(48,428)	(34,513)
Other, net	20,935	26,103	23,002
Net cash provided by (used in) investing activities	(902,294)	(1,419,652)	(1,053,203)
Cash flows from financing activities:
Net change in deposits	549,157	1,094,612	518,468
Net change in short-term borrowings	160	(4,747)	(1,192)
Proceeds from long-term borrowings	9,380,950	9,990,967	5,582,983
Payments on long-term borrowings	(9,182,536)	(9,816,286)	(5,542,831)
Payment on liabilities related to acquisition and portfolio purchase	(2,000)	(3,000)	0
Net proceeds from public offering of Series C preferred stock	0	169,302	0
Repurchases of common stock	(212,929)	(9,163)	0
Common shares sold to TCF employee benefit plans	715	23,254	5,838
Dividends paid on preferred stock	(11,588)	(19,904)	(19,388)
Dividends paid on common stock	(99,490)	(50,617)	(50,182)
Stock compensation tax (expense) benefit	0	0	(377)
Exercise of stock options	(997)	(57)	(701)
Net investment by (distribution to) non-controlling interest	10,638	9,482	8,432
Net cash provided by (used in) financing activities	310,804	1,192,379	484,186
Net change in cash and due from banks	(34,725)	12,179	(279,734)
Cash and due from banks at beginning of period	621,782	609,603	889,337
Cash and due from banks at end of period	587,057	621,782	609,603
Cash paid (received) for:
Interest on deposits and borrowings	139,026	86,411	78,930
Income taxes, net	(26,308)	62,115	23,064
Transfer of loans and leases to other assets	105,247	100,608	107,768
Transfer of loans and leases from held for investment to held for sale, net	848,941	1,320,210	2,739,126
Series B Preferred Stock
Cash flows from financing activities:
Redemption of preferred stock	(100,000)	0	0
Series A Preferred Stock
Cash flows from financing activities:
Redemption of preferred stock	$ 0	$ (172,500)	$ 0