Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2019

Retirement Benefits [Abstract]

Schedule of Net Periodic Benefit Cost Included in Non-interest Expense for the TCF Cash Balance Pension Plan and Postretirement Plan

The net periodic benefit plan (income) cost for defined benefit pension plans and postretirement benefit plans were as follows:

	Defined Benefit Pension Plans
	Three Months Ended September 30,						Nine Months Ended September 30,
(In thousands)	2019			2018			2019			2018
Interest cost	$	1,046		$	246		$	1,574		$	738
Service cost	—			—			—			—
Contractual termination cost	—			—			—			—
Return on plan assets	(949		)	(133		)	(1,223		)	(397		)
Amortization of prior service credit	—			—			—			—
Amortization of unrecognized net loss	—			—			—			—
Recognized actuarial (gain) loss	—			—			—			—
Net periodic benefit plan (income) cost	$	97		$	113		$	351		$	341

	Postretirement Benefit Plans
	Three Months Ended September 30,						Nine Months Ended September 30,
(In thousands)	2019			2018			2019			2018
Interest cost	$	41		$	28		$	101		$	83
Service cost	—			—			—			—
Recognized actuarial (gain) loss	—			—			—			—
Amortization of prior service cost	(11		)	(12		)	(35		)	(35		)
Amortization of unrecognized net loss	—			—			—			—
Net periodic benefit plan (income) cost	$	30		$	16		$	66		$	48