Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Details
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total	$ 42,130	$ 133,314	$ 30,522
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	4,996	(5,424)	(5,475)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	1,815	(1,916)	(2,013)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	3,181	(3,508)	(3,462)
Other Comprehensive Income (Loss), Net of Tax, Total	3,181	(3,508)	(3,462)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	45,311	129,806	27,060
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest
Net Income (Loss) Attributable to Noncontrolling Interest	88	10,016	578
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest	0	118	5
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest	0	118	5
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	88	10,134	583
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 45,223	$ 119,672	$ 26,477