Acquisitions - Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Jul. 01, 2019	Dec. 31, 2018
Liabilities:
Goodwill	$ 49,079		$ 47,396
Goodwill expected to be deductible for tax purposes		$ 17,900
NTA
Assets:
Investments		542,600
Cash and short-term investments		73,800
Intangible assets		169,800
Other assets		18,300
Liabilities:
Policy reserves		366,800
Policy claims		21,800
Unearned premiums		4,100
Other liabilities		5,500
Total identifiable net assets acquired		406,300
Goodwill		19,600
Purchase price		$ 425,900
Acquired finite-lived intangible assets, useful lives	23 years