Investments - Summary of Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Nov. 30, 2013
Held to maturity
Due in one year or less, Amortized Cost	$ 3,659,000
Due after one year through five years, Amortized Cost	38,127,000
Due after five years through ten years, Amortized Cost	76,922,000
Due after ten years, Amortized Cost	77,718,000
Mortgage-backed securities, Amortized Cost	99,934,000
Total held to maturity, Amortized Cost	296,360,179	240,370,277
Due in one year or less, Estimated Fair Value	3,693,000
Due after one year through five years, Estimated Fair Value	38,340,000
Due after five years through ten years, Estimated Fair Value	77,392,000
Due after ten years, Estimated Fair Value	81,890,000
Mortgage-backed securities, Estimated Fair Value	100,010,000
Total held to maturity, Estimated Fair Value	301,325,000	238,790,000	212,228,289
Available for sale
Due in one year or less, Amortized Cost	14,415,000
Due after one year through five years, Amortized Cost	66,282,000
Due after five years through ten years, Amortized Cost	126,254,000
Due after ten years, Amortized Cost	130,212,000
Mortgage-backed securities, Amortized Cost	76,018,000
Total available for sale, Amortized Cost	413,181,000
Due in one year or less, Estimated Fair Value	14,541,000
Due after one year through five years, Estimated Fair Value	68,033,000
Due after five years through ten years, Estimated Fair Value	133,077,000
Due after ten years, Estimated Fair Value	138,662,000
Mortgage-backed securities, Estimated Fair Value	77,215,000
Total available for sale, Estimated Fair Value	$ 431,527,749	$ 403,651,965