CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Net income (loss)	$ 25,646us-gaap_NetIncomeLoss	$ 17,083us-gaap_NetIncomeLoss
Available-for-sale debt securities on which an other-than-temporary impairment has been recognized:
Subsequent unrealized gain on debt securities on which an other-than-temporary impairment has been recognized	689	913
Reclassification adjustment for other-than-temporary impairment on debt securities included in net income	156	0
All other unrealized gains and losses on available-for-sale securities:
All other unrealized holding gains arising during the period	6,295	21,626
Income tax expense related to items of other comprehensive income	0us-gaap_OtherComprehensiveIncomeLossTax	0us-gaap_OtherComprehensiveIncomeLossTax
Other comprehensive income (loss) for the period, net of tax	7,140	22,539
Total comprehensive income (loss)	$ 32,786us-gaap_ComprehensiveIncomeNetOfTax	$ 39,622us-gaap_ComprehensiveIncomeNetOfTax

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Other than temporary impairment losses subsequent unrealized gain on debt securities.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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