Investments (Amortized Cost, Gross Unrealized Gains And Losses, Estimated Fair Value Of Fixed Maturity Securities) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012 Securities
Schedule of Held-to-maturity Securities [Line Items]
Securities with unrealized losses for less than 12 months	7
Foreign Corporate Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	2,001
Gross Unrealized, Gains	1
Gross Unrealized, Temporary Losses
Estimated Fair Value	2,002
U.S. Corporate Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	20,274
Gross Unrealized, Gains	3
Gross Unrealized, Temporary Losses	8
Estimated Fair Value	20,269
Total Restricted Fixed Maturity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	22,275
Gross Unrealized, Gains	4
Gross Unrealized, Temporary Losses	8
Estimated Fair Value	22,271