UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income (loss) before income taxes	$ 30,179	$ (31,621)
Net income (loss)	22,710	(17,404)
Other Comprehensive Income, Net of Tax	15,862
Before Tax Amount [Member]
Income (loss) before income taxes	30,179	(31,621)
Unrealized Gains on Investment Securities, Before Tax	24,298	(12,933)
Net gains (losses) on sales of investment securities realized in net income, Before Tax	8	25
Unrealized gains (losses) on investment securities, before tax	24,290	(12,958)
Pension Adjustment, Before Tax	114	113
Other Comprehensive Income (Loss), Before Tax	24,404	(12,845)
Comprehensive Income Before Tax	54,583	(44,466)
Tax Expense (Benefit) [Member]
Net Income, Tax Expense	7,469	(14,217)
Unrealized holding gains (losses) arising during the period, Tax	8,505	(4,528)
Net gains (losses) on sales of investment securities realized in net income, Tax	3	9
Unrealized Gains on Investment Securities, Tax Expense	8,502	(4,537)
Pension Adjustment, Tax Expense	40	40
Other Comprehensive Income (Loss), Tax	8,542	(4,497)
Comprehensive Income, Tax Expense	16,011	(18,714)
Net of Tax Amount [Member]
Net income (loss)	22,710	(17,404)
Unrealized holding gains (losses) arising during the period, Net of Tax	15,793	(8,405)
Net gains (losses) on sales of investment securities realized in net income, net of tax	5	16
Unrealized Gains (losses) on investment securities, net of tax	15,788	(8,421)
Pension Adjustment, Net of Tax	74	73
Other Comprehensive Income, Net of Tax	15,862	(8,348)
Total comprehensive income	$ 38,572	$ (25,752)