Net Investment Income (Schedule of Net Investment Income) (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments Debt And Equity Securities [Abstract]
Cash equivalents and deposits with banks		$ 3,822	$ 4,471	$ 3,694
Debt securities		76,822	56,373	47,226
Other investments		1,841	1,213	2,009
Loans receivable			3,755	5,474
Dividends on equity securities		11,751	11,961	11,776
Equity in earnings of affiliates, net		7,800	(16,545)	5,316
Other		314	10,488	14,400
Total investment income		102,350	71,716	89,895
Investment expenses	[1]	(1,797)	(675)
Net investment income		$ 100,553	$ 71,041	$ 89,895

[1] Investment expenses include fees paid to third party investment managers, which the Company began utilizing in 2014.