Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 14,931	$ 30,890
Unrealized gains on available for sale debt securities:
Net unrealized gains arising during the period	16,746	7,578
Reclassification adjustment for gains included in net income	0	0
Total	16,746	7,578
Unrealized losses on derivatives	(5,713)	(314)
Amortization related to post-retirement obligations	84	(12)
Total other comprehensive income	11,117	7,252
Total comprehensive income	$ 26,048	$ 38,142

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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