Derivative Instruments - Derivatives Not Designated as Hedging Instruments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest rate contracts
Derivative, Collateral
Cash collateral posted	$ 9,100,000
Forward foreign exchange contracts
Credit risk-related contingent features
Forward foreign exchange contracts with credit risk-related contingent features, notional value	25,700,000	$ 39,800,000
Additional collateral required, if TCF was rated less than BB- by Standard and Poor's	500,000	800,000
Forward foreign exchange contracts with credit risk-related contingent features, net liability amount	0	400,000
Derivative, Collateral
Cash collateral received	6,700,000
Other contracts
Derivative, Collateral
Cash collateral posted	1,300,000
Derivatives not designated as hedges
Derivatives instruments, gain (loss)
Effect of derivatives included in the Consolidated Statements of Income	23,830,000	(16,400,000)	$ (14,666,000)
Derivatives not designated as hedges | Interest rate contracts | Other non-interest income
Derivatives instruments, gain (loss)
Effect of derivatives included in the Consolidated Statements of Income	(409,000)	(268,000)	71,000
Derivatives not designated as hedges | Forward foreign exchange contracts | Other non-interest expense
Derivatives instruments, gain (loss)
Effect of derivatives included in the Consolidated Statements of Income	23,707,000	(15,748,000)	(13,689,000)
Derivatives not designated as hedges | Interest rate lock commitments | Gains on sales loans, net
Derivatives instruments, gain (loss)
Effect of derivatives included in the Consolidated Statements of Income	806,000	(73,000)	(419,000)
Derivatives not designated as hedges | Other contracts | Other non-interest expense
Derivatives instruments, gain (loss)
Effect of derivatives included in the Consolidated Statements of Income	$ (274,000)	$ (311,000)	$ (629,000)