Deferred Policy Acquisition Costs Deferred Costs, Capitalized, Prepaid, and Other Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred policy acquisition costs, beg. balance	$ 65,473	$ 46,732
Deferred Policy Acquisition Costs, Additions	210,324	134,588
Amortization	(171,915)	(115,847)
Deferred policy acquisition costs, end. balance	$ 103,882	$ 65,473