Parent Company Financial Information - Condensed Statements of Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-interest income:
Other		$ 13,843	$ 11,646	$ 8,883
Non-interest expense:
Compensation and employee benefits		497,063	482,512	475,964
Occupancy and equipment		165,812	156,909	149,980
Other		260,646	346,856	230,397
Total non-interest expense		1,014,400	1,059,934	909,887
Income before income tax expense (benefit)		401,724	245,160	338,245
Income tax benefit		(86,096)	33,624	(116,528)
Net income attributable to TCF Financial Corporation		304,358	268,637	212,124
Preferred stock dividends		11,588	19,904	19,388
Impact of preferred stock redemption	[1]	3,481	5,779	0
Net income available to common stockholders		289,289	242,954	192,736
TCF Financial Corporation
Interest income:
Interest income		200	183	155
Non-interest income:
Dividends from TCF Bank		431,000	65,000	63,000
Management fees		20,532	15,660	17,657
Other		426	13	5
Total non-interest Income		451,958	80,673	80,662
Non-interest expense:
Compensation and employee benefits		21,825	17,801	17,578
Occupancy and equipment		301	275	370
Other		4,139	1,785	3,545
Total non-interest expense		26,265	19,861	21,493
Income before income tax expense (benefit)		425,893	60,995	59,324
Income tax benefit		952	1,575	1,010
Income before equity in undistributed earnings (loss) of TCF Bank		426,845	62,570	60,334
Equity in undistributed earnings (loss) of TCF Bank		(122,487)	206,067	151,790
Net income attributable to TCF Financial Corporation		304,358	268,637	212,124
Preferred stock dividends		11,588	19,904	19,388
Impact of preferred stock redemption		3,481	5,779	0
Net income available to common stockholders		$ 289,289	$ 242,954	$ 192,736

[1] Amounts represent the deferred stock issuance costs originally recorded in preferred stock that were reclassified to retained earnings.