RECENT DEVELOPMENTS AND SIGNIFICANT EVENTS RECENT DEVELOPMENTS AND SIGNIFICANT EVENTS (Details) shares in Thousands, $ in Thousands			6 Months Ended
	Mar. 06, 2015 USD ($)	Nov. 05, 2014 USD ($) shares	Jun. 30, 2015 USD ($) bank_branch state
AmericanWest Bank [Member]
Business Acquisition [Line Items]
Total assets acquired			$ 4,600,000
Loans receivable			3,000,000
Deposits			3,600,000
Equity of acquired entity			$ 594,000
Equity interests issued and issuable | shares		13,230
Cash paid		$ 130,000
Acquiree equity interest in acquirer		38.80%
Number of branch offices in which entity operates | bank_branch			190
Number of states in which entity operates | state			5
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Total assets acquired	$ 370,306
Loans receivable	247,098
Deposits	316,406
Cash paid	$ 5,806
Number of branches acquired | bank_branch			10