Deferred Policy Acquisition Costs (Tables)

12 Months Ended

Dec. 31, 2017

Deferred Policy Acquisition Costs Disclosures [Abstract]

Amounts Of Policy Acquisition Costs Deferred And Amortized

The following table presents the amounts of policy acquisition costs deferred and amortized.

	Years Ended December 31,
(dollars in thousands)	2017			2016			2015
Balance, beginning of year	$	392,410		$	352,756		$	353,410
Policy acquisition costs deferred	964,755			823,840			752,324
Amortization of policy acquisition costs	(894,353		)	(782,221		)	(744,964		)
Foreign currency movements	2,757			(1,965		)	(8,014		)
Deferred policy acquisition costs	$	465,569		$	392,410		$	352,756

Components Of Underwriting, Acquisition And Insurance Expenses

The following table presents the components of underwriting, acquisition and insurance expenses.

	Years Ended December 31,
(dollars in thousands)	2017		2016		2015
Amortization of policy acquisition costs	$	894,353	$	782,221	$	744,964
Other operating expenses	693,061		716,369		710,116
Underwriting, acquisition and insurance expenses	$	1,587,414	$	1,498,590	$	1,455,080