General - Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net unrealized investment losses recognized on equity securities still held	$ (2,162)	$ 0	$ 0
Retained Earnings | ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net unrealized investment losses recognized on equity securities still held	4,600
AOCI | ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net unrealized investment losses recognized on equity securities still held	(4,600)
ASU 2018-02 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of net tax expense from AOCI to retained earnings	$ 1,000