Scheduled Maturity Dates for Fixed Maturity Securities by Number of Years Until Maturity (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value
Due in one year or less	$ 85,240
Due after one year through five years	627,515
Due after five years through ten years	443,197
Due after ten years	251,009
Mortgage- and asset-backed securities	640,912
Total	2,047,873	2,121,833
Amortized Cost
Due in one year or less	84,691
Due after one year through five years	615,267
Due after five years through ten years	446,918
Due after ten years	258,480
Mortgage- and asset-backed securities	631,643
Total	$ 2,036,999	$ 2,034,765