TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets
Cash and Cash equivalents	$ 598,368	$ 748,899	$ 637,275	$ 371,066
Other assets	35,880	38,607
Total assets	2,744,066	2,609,269
Liabilities and shareholders' equity
Other liabilities	31,711	35,122
Junior subordinated debt	41,238	41,238
Total liabilities	2,493,120	2,379,910
Shareholders' equity:
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 16,076,662 and 16,000,838 shares, respectively	89,356	85,561
Retained earnings	159,733	141,639
Accumulated other comprehensive loss, net	1,857	2,159
Total shareholders' equity	250,946	229,359	216,441	200,397
Total liabilities and shareholders' equity	2,744,066	2,609,269
Parent [Member]
Assets
Cash and Cash equivalents	2,520	2,511	706	633
Investment in Tri Counties Bank	288,746	267,118
Other assets	1,280	1,238
Total assets	292,546	270,867
Liabilities and shareholders' equity
Other liabilities	362	270
Junior subordinated debt	41,238	41,238
Total liabilities	41,600	41,508
Shareholders' equity:
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 16,076,662 and 16,000,838 shares, respectively	89,356	85,561
Retained earnings	159,733	141,639
Accumulated other comprehensive loss, net	1,857	2,159
Total shareholders' equity	250,946	229,359
Total liabilities and shareholders' equity	$ 292,546	$ 270,867