WORKERS' COMPENSATION LOSS RESERVES

The following table summarizes the workers’ compensation loss reserve activity for the three months ended March 31, 2018 and 2017:



	Three Months Ended March 31,
(in millions)	2018			2017
Total loss reserves, beginning of period	$	255		$	255
Incurred
Current year	20			27
Prior years	(7		)	1
Total incurred	13			28
Paid
Current year	—			—
Prior years	(18		)	(22		)
Total paid	(18		)	(22		)
Total loss reserves, end of period	$	250		$	261

The following summarizes workers' compensation liabilities on the condensed consolidated balance sheets:



(in millions)	March 31, 2018			December 31, 2017
Total loss reserves, end of period	$	250		$	255
Collateral paid to carriers and offset against loss reserves	(21		)	(23		)
Total loss reserves, net of carrier collateral offset	$	229		$	232

Payable in less than 1 year (net of collateral paid to carriers of $5 and $6 at March 31, 2018 and December 31, 2017, respectively)	$	67		$	67
Payable in more than 1 year (net of collateral paid to carriers of $16 and $17 at March 31, 2018 and December 31, 2017, respectively)	162			165
Total loss reserves, net of carrier collateral offset	$	229		$	232

Incurred claims related to prior years represent changes in estimates for ultimate losses on workers' compensation claims. For the three months ended March 31, 2018, the favorable development was primarily due to lower than expected severity of reported claims associated with office and non-office worker WSEs in recent accident years.

As of March 31, 2018 and December 31, 2017, we had $61 million and $63 million, respectively, of collateral held by insurance carriers of which $21 million and $23 million, respectively, was offset against workers' compensation loss reserves as the agreements permit and are net settled of insurance obligations against collateral held. Collateral paid to each carrier for a policy year in excess of our loss reserves is recorded as workers' compensation collateral receivable.