CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OTHER COMPREHENSIVE INCOME (LOSS)
Change in unrealized holding gains (losses) on investment securities, deferred income tax expense (benefit)	$ 18,664	$ (8,390)	$ 12,849
Reclassification adjustment for realized investment (gains) losses included in net income (loss), income tax (expense) benefit	(2,518)	(3,149)	(2,806)
Reclassification adjustment for amounts amortized into net periodic pension and postretirement benefit cost (income), deferred income tax (expense) benefit	(955)	765	950
Change in funded status of affiliate's pension and postretirement benefit plans, deferred income tax expense (benefit)	$ (2,994)	$ 16,836	$ (2)