Consolidated Statements of Financial Condition (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Cash and cash equivalents:
Cash and due from banks	$ 585,663	$ 531,918
Interest-bearing deposits with other banks	463,641	728,677
Total cash and cash equivalents	1,049,304	1,260,595
Federal Home Loan Bank and Federal Reserve Bank stocks, at cost	358,414	320,436
Investment securities:
Available-for-sale, at fair value (amortized cost of $8,396,973 and $8,041,173)	8,403,788	8,284,723
Held-to-maturity, at amortized cost (fair value of $212,411 and $193,554)	209,778	184,359
Total investment securities	8,613,566	8,469,082
Loans and leases held-for-sale (includes $107,417 and $22,178 at fair value)	107,649	222,028
Loans and leases	36,221,019	34,466,408
Allowance for loan and lease losses	(504,645)	(525,868)
Loans and leases, net	35,716,374	33,940,540
Premises and equipment, net	455,032	470,131
Goodwill	1,379,890	1,313,046
Other intangible assets, net	149,438	146,377
Loan servicing rights	44,151	38,303
Other assets	1,585,733	1,621,949
Total assets	49,459,551	47,802,487
Deposits:
Noninterest-bearing	12,394,753	11,036,086
Interest-bearing	27,392,061	27,820,233
Total deposits	39,786,814	38,856,319
Short-term borrowings	1,426,083	617,363
Long-term borrowings	1,518,816	1,374,732
Other liabilities	1,136,067	1,264,776
Total liabilities	43,867,780	42,113,190
Equity
Preferred stock issued	169,302	169,302
Common stock issued	152,696	152,566
Additional paid-in capital	3,466,655	3,457,802
Retained earnings	1,802,340	1,735,201
Accumulated other comprehensive income	2,654	182,673
Other	(29,813)	(26,731)
Total TCF Financial Corporation shareholders' equity	5,563,834	5,670,813
Non-controlling interest	27,937	18,484
Total equity	5,591,771	5,689,297
Total liabilities and equity	$ 49,459,551	$ 47,802,487
Preferred Stock, Par or Stated Value Per Share	$ 0	$ 0
Preferred Stock, Shares Authorized	2,000,000	2,000,000
Preferred Stock, Shares Issued	7,000	7,000
Common Stock, Par or Stated Value Per Share	$ 1.00	$ 1.00
Common Stock, Shares Authorized	220,000,000	220,000,000