Discontinued Operations - Income from Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Benefits and expenses:
Income from discontinued operations	$ 10,636	$ 9,959	$ (865)	$ (9,541)	$ 13,826	$ 11,528	$ (5,417)	$ (9,130)	$ 10,189	$ 10,807	$ 14,865
Income taxes paid									79,790	110,650	100,922
Medicare Part D
Revenue:
Health premium									222,840	260,657	373,280
Benefits and expenses:
Health policyholder benefits									183,423	213,114	315,816
Amortization of deferred acquisition costs									3,747	3,506	2,858
Commissions, premium taxes, and non-deferred acquisition expenses									16,396	20,909	26,613
Other operating expense									5,377	6,502	5,123
Total benefits and expenses									208,943	244,031	350,410
Income before income taxes for discontinued operations									13,897	16,626	22,870
Gain from sale of discontinued operations									1,779	0	0
Income taxes									(5,487)	(5,819)	(8,005)
Income from discontinued operations									10,189	10,807	14,865
Discontinued Operations | Medicare Part D
Benefits and expenses:
Income taxes paid									$ 15,271	$ 3,409	$ 12,013