Other Assets - Summary of Other Assets (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred tax asset, net	$ 27,957		$ 26,781
Prepaid expense	1,937		2,131
Software	1,222		1,318
Advanced compensation	990		1,175
TriCo Capital Trust I & II	1,238		1,238
Indemnification asset (Note 11)	(3)	(37)	206	861	1,441	1,997
Miscellaneous other assets	1,230		3,237
Total other assets	$ 34,571		$ 36,086