Tax Effects of Temporary Differences That Give Rise to Federal, Foreign, State and Local Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Loss reserve discount	$ 25,420	$ 25,353
Unearned premiums	33,886	31,486
Compensation related	15,288	11,175
State and local net deferred tax assets	699	721
Net currency translation adjustments	5,363	346
Other	3,618	3,969
Total gross deferred tax assets	84,274	73,050
Less: Valuation allowance	(699)	(721)
Total deferred tax assets	83,575	72,329
Deferred tax liabilities:
Net unrealized gains/losses on securities	(10,142)	(13,053)
Deferred acquisition costs	(29,401)	(24,037)
Net unrealized foreign exchange	(3,575)	(4,164)
Other	(4,048)	(2,709)
Total deferred tax liabilities	(62,637)	(68,429)
Net deferred income tax asset (liability)	20,938	3,900
Lloyd's
Deferred tax liabilities:
Lloyd's year of account deferral	$ (15,471)	$ (24,466)