Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net income (loss), Before-tax Amount	$ 252,628		$ 31,477		$ (59,532)
Net income (loss), Tax (expense) Benefit	(93,245)		798,732		(1,312)
Net income (loss), Net of Tax Amount	159,383		830,209		(60,844)
Net change related to cash flow hedges: Before-tax Amount
Reclassification adjustment for losses (gains) realized in net income, Before-tax Amount	447		(1,381)		(11,316)
Valuation allowance for the change in deferred taxes arising from unrealized gains/losses, Before-tax Amount	0	[1]	0	[1]	0	[1]
Net change, Before-tax Amount	447		(1,381)		(11,316)
Net change related to cash flow hedges: Tax (Expense) Benefit
Reclassification adjustment for losses (gains) realized in net income, Tax (Expense) Benefit	(173)		532		4,279
Valuation allowance for the change in deferred taxes arising from unrealized gains/losses, Tax (Expense) Benefit	0	[1]	0	[1]	(4,279)	[1]
Net change, Tax (Expense) Benefit	(173)		532		0
Net change related to cash flow hedges: Net of Tax Amount
Reclassification adjustment for losses (gains) realized in net income, Net of Tax Amount	274		(849)		(7,037)
Valuation allowance for the change in deferred taxes arising from unrealized gains/losses, Net of Tax Amount	0	[1]	0	[1]	(4,279)	[1]
Net change, Net of Tax Amount	274		(849)		(11,316)
Net unrealized gains/losses on investment securities available for sale: Before-tax Amount
Reclassification adjustment for gains realized in net income, Before-tax Amount	(2,945)		(39,142)		(75,007)
Net unrealized (losses) gains arising during the period, Before-tax Amount	(71,929)		12,296		50,258
Valuation allowance for the change in deferred taxes arising from unrealized gains/losses, Before-tax Amount	0	[1]	0	[1]	0	[1]
Net unrealized losses, Before-tax Amount	(74,874)		(26,846)		(24,749)
Net unrealized gains/losses on investment securities available for sale: Tax (Expense) Benefit
Reclassification adjustment for gains realized in net income, Tax (Expense) Benefit	1,134		15,070		29,271
Net unrealized (losses) gains arising during the period, Tax (Expense) Benefit	27,693		(4,730)		(19,349)
Valuation allowance for the change in deferred taxes arising from unrealized gains/losses, Tax (Expense) Benefit	0	[1]	0	[1]	(9,922)	[1]
Net unrealized losses, Tax (Expense) Benefit	28,827		10,340		0
Net unrealized gains/losses on investment securities available for sale: Net of Tax Amount
Reclassification adjustment for gains realized in net income, Net of Tax Amount	(1,811)		(24,072)		(45,736)
Net unrealized (losses) gains arising during the period, Net of Tax Amount	(44,236)		7,566		30,909
Valuation allowance for the change in deferred taxes arising from unrealized gains/losses, Net of Tax Amount	0	[1]	0	[1]	(9,922)	[1]
Net unrealized losses, Net of Tax Amount	(46,047)		(16,506)		(24,749)
Post-retirement unfunded health benefit: Before-tax Amount
Reclassification adjustment for gains realized in net income, Before-tax Amount	(170)		(52)		0
Actuarial gains arising during the period, Before-tax Amount	830		642		0
Net unrealized gains, Before-tax Amount	660		590		0
Post-retirement unfunded health benefit: Tax (Expense) Benefit
Reclassification adjustment for gains realized in net income, Tax (Expense) Benefit	65		20		0
Actuarial gains arising during the period, Tax (Expense) Benefit	(311)		(247)		0
Net unrealized gains, Tax (Expense) Benefit	(246)		(227)		0
Post-retirement unfunded health benefit: Net of Tax Amount
Reclassification adjustment for gains realized in net income, Net of Tax Amount	(105)		(32)		0
Actuarial gains arising during the period, Net of Tax Amount	519		395		0
Net unrealized gains, Net of Tax Amount	414		363		0
Other comprehensive income (loss), Before-tax Amount	(73,767)		(27,637)		(36,065)
Less: comprehensive loss attributable to non-controlling interest, Before-tax Amount	0		0		(220)
Other comprehensive income (loss), Tax (Expense) Benefit	28,408		10,645		0
Less: comprehensive loss attributable to non-controlling interest, Tax (Expense) Benefit	0		0		0
Other comprehensive income (loss), Net of Tax Amount	(45,359)		(16,992)		(36,065)
Less: comprehensive loss attributable to non-controlling interest, Net of Tax Amount	0		0		(220)
Comprehensive income (loss), Net of Tax Amount	$ 114,024		$ 813,217		$ (96,689)

[1] In accordance with ASC 740-20-45-11(b), the deferred tax asset valuation allowance associated with unrealized gains and losses not recognized in income is charged directly to other comprehensive income (loss).