Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Valuation of financial instruments that are marked-to-market on recurring basis

The following table summarizes the valuation of our financial instruments that are marked to fair value on a recurring basis.

	Fair Value Measurements on a Recurring Basis
	March 31, 2020								December 31, 2019
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Available-for-sale investments	$	—	$	538,742	$	75,840	$	614,582	$	—	$	487,669	$	—	$	487,669
Derivative instruments	—		3,653		—		3,653		—		715		—		715
Total	$	—	$	542,395	$	75,840	$	618,235	$	—	$	488,384	$	—	$	488,384
Liabilities
Derivative instruments	$	—	$	(275)	$	—	$	(275)	$	—	$	(1,164)	$	—	$	(1,164)
Total	$	—	$	(275)	$	—	$	(275)	$	—	$	(1,164)	$	—	$	(1,164)

Fair values of financial assets and liabilities, including derivative financial instruments

The following table summarizes the fair values of our financial assets and liabilities, including derivative financial instruments.

	March 31, 2020						December 31, 2019
	Fair Value		Carrying Value		Difference		Fair Value		Carrying Value		Difference
Earning assets:
Loans held for investment, net:
Private Education Loans	$	21,826,300	$	20,176,233	$	1,650,067	$	24,988,941	$	22,896,515	$	2,092,426
FFELP Loans	755,449		764,771		(9,322)		795,055		783,816		11,239
Personal Loans	851,750		747,444		104,306		1,047,119		983,643		63,476
Credit Cards	6,959		7,403		(444)		3,818		3,818		—
Cash and cash equivalents	7,292,929		7,292,929		—		5,563,877		5,563,877		—
Trading investments	11,360		11,360		—		—		—		—
Available-for-sale investments	614,582		614,582		—		487,669		487,669		—
Accrued interest receivable	1,291,972		1,281,746		10,226		1,491,471		1,392,725		98,746
Tax indemnification receivable	27,727		27,727		—		27,558		27,558		—
Derivative instruments	3,653		3,653		—		715		715		—
Total earning assets	$	32,682,681	$	30,927,848	$	1,754,833	$	34,406,223	$	32,140,336	$	2,265,887
Interest-bearing liabilities:
Money-market and savings accounts	$	10,360,970	$	10,314,072	$	(46,898)	$	10,363,691	$	10,335,163	$	(28,528)
Certificates of deposit	14,202,601		14,129,891		(72,710)		14,065,007		13,947,743		(117,264)
Short-term borrowings	—		—		—		289,230		289,230		—
Long-term borrowings	4,572,625		4,708,036		135,411		4,434,323		4,354,037		(80,286)
Accrued interest payable	93,768		93,768		—		75,158		75,158		—
Derivative instruments	275		275		—		1,164		1,164		—
Total interest-bearing liabilities	$	29,230,239	$	29,246,042	$	15,803	$	29,228,573	$	29,002,495	$	(226,078)
Excess of net asset fair value over carrying value					$	1,770,636					$	2,039,809