INVESTMENT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of Investment Securities

	March 31, 2019									December 31, 2018
(In millions)	Amortized cost		Gross unrealized gains		Gross unrealized losses (a)			Estimated fair value (b)		Amortized cost		Gross unrealized gains		Gross unrealized losses (a)			Estimated fair value (b)
Debt
U.S. corporate	$	21,390	$	2,903	$	(71	)	$	24,222	$	21,306	$	2,257	$	(357	)	$	23,206
Non-U.S. corporate	1,848		96		(12		)	1,932		1,906		53		(76		)	1,883
State and municipal	3,136		455		(37		)	3,555		3,320		367		(54		)	3,633
Mortgage and asset-backed	3,184		75		(15		)	3,244		3,325		51		(54		)	3,322
Government and agencies	1,604		79		(1		)	1,682		1,603		63		(20		)	1,645
Equity(a)	3,639		—		—			3,639		146		—		—			146
Total	$	34,802	$	3,608	$	(134	)	$	38,275	$	31,605	$	2,792	$	(561	)	$	33,835

(a) Primarily comprises interest in Wabtec that was received as consideration from the merger of our Transportation business with Wabtec as described in Note 2. Net unrealized gains (losses) recorded to earnings for equity securities were $19 millionand $(29) million for the three months ended March 31, 2019 and 2018, respectively.

Contractual Maturities of Investment in Available-for-Sale Debt Securities (Excluding Mortgage and Asset-Backed Securities)

CONTRACTUAL MATURITIES OF INVESTMENT IN AVAILABLE-FOR-SALE DEBT SECURITIES (EXCLUDING MORTGAGE AND ASSET-BACKED SECURITIES) (In millions)	Amortized cost		Estimated fair value
Due(a)
Within one year	$	434	$	436
After one year through five years	2,957		3,092
After five years through ten years	6,117		6,741
After ten years	18,532		21,195

(a) We expect actual maturities to differ from contractual maturities because borrowers have the right to call or prepay certain obligations.