Commitments and Contingencies - Narrative (Details) $ in Thousands		9 Months Ended
	Mar. 31, 2016 USD ($) defendant plaintiff	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Loss Contingencies [Line Items]
Residential mortgage principal balance repurchase request received		$ 543	$ 543
Residential mortgage principal balance FHLB credit enhancement		89,000
Residential mortgage repurchase reserves FHLB credit enhancement		1,300	1,700
Agostino, et al. v. Ameriprise Financial Services, Inc [Member]
Loss Contingencies [Line Items]
Number of unrelated defendants | defendant	2
Amount alleged in damages	$ 11,300
Agostino, et al. v. Ameriprise Financial Services, Inc [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff	67
Reserve for Off-balance Sheet Activities [Member] | Residential Mortgage [Member]
Loss Contingencies [Line Items]
Valuation allowances and reserves, balance		$ 2,100	$ 2,500