Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2017

Schedule of assets and liabilities measured at fair vale on a recurring basis

All assets measured at fair value are categorized in the table below based upon the lowest level of significant input to the valuations. All fair value measurements at the reporting date were on a recurring basis.



March 31, 2017 (In thousands)	Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Recurring fair value measurements
Financial Assets:
U.S. Treasury securities	$	178,743	$	—	$	—	$	178,743
U.S. agency securities	—		26,284		—		26,284
U.S. agency mortgage-backed securities	—		355,239		—		355,239
Municipal debt securities	—		361,392		—		361,392
Corporate debt securities	—		505,288		—		505,288
Residential and commercial mortgage securities	—		65,288		—		65,288
Asset-backed securities	—		134,911		—		134,911
Money market funds	97,388		—		—		97,388
Total assets at fair value	$	276,131	$	1,448,402	$	—	$	1,724,533



December 31, 2016 (In thousands)	Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Recurring fair value measurements
Financial Assets:
U.S. Treasury securities	$	191,548	$	—	$	—	$	191,548
U.S. agency securities	—		18,441		—		18,441
U.S. agency mortgage-backed securities	—		316,494		—		316,494
Municipal debt securities	—		334,324		—		334,324
Corporate debt securities	—		456,357		—		456,357
Residential and commercial mortgage securities	—		68,336		—		68,336
Asset-backed securities	—		127,172		—		127,172
Money market funds	102,430		—		—		102,430
Total assets at fair value	$	293,978	$	1,321,124	$	—	$	1,615,102

Schedule of changes during period in Level 3 liabilities measured at fair value on a recurring basis, and realized and unrealized gains (losses) related to Level 3 liabilities

The following table presents changes during the three months ended March 31, 2016 in Level 3 liabilities measured at fair value on a recurring basis, and the net realized and unrealized losses (gains) related to the Level 3 liabilities in the condensed consolidated balance sheets at March 31, 2016. During the three months ended March 31, 2017, and in the year ended December 31, 2016, we had no Level 3 assets.



	Three Months Ended March 31,
(In thousands)	2016
Level 3 Liabilities
Fair value of derivative liabilities at beginning of period	$	1,232
Net realized and unrealized losses (gains) included in income	(677		)
Other comprehensive (income) loss	—
Purchases, sales, issues and settlements, net	343
Gross transfers in	—
Gross transfers out	—
Fair value of derivative liabilities at end of period	$	898

Changes in net unrealized losses (gains) included in income on instruments held at end of period	$	(677	)