Fair Value Measurement - Methodologies Other Than Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Carrying Value
Financial assets:
Other assets	$ 35,921	$ 34,020
Financial liabilities:
Other liabilities	21,300	21,154
Carrying Value | Senior Notes
Financial liabilities:
Debt	250,000	250,000
Carrying Value | Line of Credit
Financial liabilities:
Debt	0	123,000
Carrying Value | Mortgage Loans
Financial liabilities:
Debt	39,064	40,460
Fair Value
Financial assets:
Other assets	35,468	33,742
Financial liabilities:
Other liabilities	21,300	21,154
Fair Value | Senior Notes
Financial liabilities:
Debt	264,810	273,153
Fair Value | Line of Credit
Financial liabilities:
Debt	0	123,000
Fair Value | Mortgage Loans
Financial liabilities:
Debt	39,064	40,460
BOLI | Carrying Value
Financial assets:
Other investments	64,096	62,113
BOLI | Fair Value
Financial assets:
Other investments	64,096	62,113
Other investments | Carrying Value
Financial assets:
Other investments	2,943	58,546
Other investments | Fair Value
Financial assets:
Other investments	$ 2,943	$ 69,095