Fair Value - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair value, assets, level 2 to level 1, transfers	$ 0	$ 0	$ 0	$ 0
Fair value, assets, level 1 to level 2, transfers	0	$ 0	0	$ 0
Other invested assets overseas deposit	37,000,000		37,000,000		$ 31,000,000
Life settlement contracts, escrow amount	1,000,000		$ 1,000,000
Life settlement contracts, receivable, payment period			3 years
Life settlement contracts, fair value	$ 1,000,000		$ 1,000,000		$ 58,000,000