Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)
Statement of Stockholders' Equity [Abstract]
Capitalized issuance costs	$ 163

It represents amount of capitalized issuance costs resulting from common stock issued during the period.

No definition available.

Name:	ncbs_CommonStockIssuedCapitalizedIssuanceCosts
Namespace Prefix:	ncbs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration