Business Combinations - Fair Value of Net Assets Acquired (Details) - Ozark National Life Insurance Company $ in Thousands	Jan. 31, 2019 USD ($)
Assets
Debt securities held to maturity	$ 261,059
Debt securities available for sale	400,719
Policy loans	28,128
Real estate	4,600
Cash and cash equivalents	16,275
Accrued investment income	6,116
Value of business acquired	145,768
Reinsurance recoverables	21,895
Other intangible assets	9,600
Other assets acquired	12,075
Total assets acquired	906,235
Liabilities
Traditional life reserves	691,297
Other policyholder liabilities	13,867
Other liabilities acquired	5,840
Total liabilities acquired	711,004
Net identifiable assets acquired	195,231
Goodwill	13,864
Net assets acquired	$ 209,095