Resale and Repurchase Agreements Resale and Repurchase Agreements (Tables)

12 Months Ended

Dec. 31, 2018

Offsetting [Abstract]

Offsetting, Resale and Repurchase Agreements [Table Text Block]

								Gross Amounts Not Offset in the Balance Sheet
(In thousands)	Gross Amount Recognized		Gross Amounts Offset in the Balance Sheet			Net Amounts Presented in the Balance Sheet		Financial Instruments Available for Offset		Securities Collateral Received/Pledged			Net Amount
December 31, 2018
Total resale agreements, subject to master netting arrangements	$	1,150,000	$	(450,000	)	$	700,000	$	—	$	(700,000	)	$	—
Total repurchase agreements, subject to master netting arrangements	2,393,219		(450,000		)	1,943,219		—		(1,943,219		)	—
December 31, 2017
Total resale agreements, subject to master netting arrangements	$	1,350,000	$	(650,000	)	$	700,000	$	—	$	(700,000	)	$	—
Total repurchase agreements, subject to master netting arrangements	1,954,768		(650,000		)	1,304,768		—		(1,304,768		)	—

Schedule of Underlying Assets of Repurchase Agreements [Table Text Block]

The table below shows the remaining contractual maturities of repurchase agreements outstanding at December 31, 2018 and 2017, in addition to the various types of marketable securities that have been pledged by the Company as collateral for these borrowings.

	Remaining Contractual Maturity of the Agreements
(In thousands)	Overnight and continuous		Up to 90 days		Greater than 90 days		Total
December 31, 2018
Repurchase agreements, secured by:
U.S. government and federal agency obligations	$	387,541	$	150,000	$	100,000	$	637,541
Government-sponsored enterprise obligations	18,466		—		—		18,466
Agency mortgage-backed securities	882,744		31,774		213,752		1,128,270
Non-agency mortgage-backed securities	187,740		—		—		187,740
Asset-backed securities	322,680		—		—		322,680
Other debt securities	98,522		—		—		98,522
Total repurchase agreements, gross amount recognized	$	1,897,693	$	181,774	$	313,752	$	2,393,219
December 31, 2017
Repurchase agreements, secured by:
U.S. government and federal agency obligations	$	271,820	$	1,731	$	450,000	$	723,551
Government-sponsored enterprise obligations	149,111		—		—		149,111
Agency mortgage-backed securities	737,975		9,750		200,000		947,725
Asset-backed securities	89,601		30,000		—		119,601
Other debt securities	14,780		—		—		14,780
Total repurchase agreements, gross amount recognized	$	1,263,287	$	41,481	$	650,000	$	1,954,768