23. Shareholders' Equity (Details Narrative) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Shareholders Equity Details Narrative
Subscribed and paid-in capital stock	556,405,096
Common shares outstanding	28,935,260	28,944,097
Shares held in treasury	13,041,356	13,131,356
Retention of profits and investments reserve	R$ 3,130,935	R$ 3,915,964
Proposed dividends payable	R$ 489,027	R$ 472,650

Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.

No definition available.

Name:	dei_EntityCommonStockSharesOutstanding
Namespace Prefix:	dei_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant