Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Future Tax Benefits

Future Tax Benefits
	As of
	March 31, 2018				Expiration
	Carryover amount		Expected tax benefit, gross		Dates			Amount
Net operating loss carryover - U.S.	$	3,087	$	648	2020			$	1
					2023	-	2036	$	3,086
Net operating loss carryover - foreign	$	4	$	—	No expiration			$	4
Foreign tax credit carryover	$	21	$	21	2023	-	2024	$	21
General business credit carryover	$	3	$	3	2031	-	2037	$	3

Income Tax Rate Reconciliation

Income Tax Rate Reconciliation
	Three Months Ended March 31,
	2018			2017
Tax provision at U.S. federal statutory rate [1]	$	109		$	140
Tax-exempt interest	(17		)	(30		)
Executive compensation	4			—
Stock-based compensation	(2		)	(7		)
Tax reform	(3		)	—
Other	—			(5		)
Provision for income taxes	$	91		$	98

[1]Due to the passage of tax reform on December 22, 2017, current and prior period federal statutory rates are reflected at 21% and 35% respectively.

Roll-forward of Unrecognized Tax Benefits

Rollforward of Unrecognized Tax Benefits
	Three Months Ended March 31,
	2018		2017
Balance, beginning of period	$	9	$	12
Gross increases - tax positions in prior period	—		—
Gross decreases - tax positions in prior period	—		—
Balance, end of period	$	9	$	12