Reorganization (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 40,492	$ 37,828	$ 29,045	$ 17,544	$ 0	$ 0
Charges	6,358	19,417	17,156	26,735	41,738	0
Non-cash adjustment					(24,194)
Cash payments	(15,720)	(16,753)	(8,373)	(15,234)	0	0
Restructuring reserve, ending balance	31,130	40,492	37,828	29,045	17,544	0
Amount expected to be incurred, including charges to date	121,506
Premium deficiency reserves
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	91,574
Restructuring reserve, ending balance	79,422	91,574
Premium deficiency charges	182,627
Amount expected to be incurred, including charges to date	304,133
Severance and retention
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	34,945	36,565	24,634	14,435	0	0
Charges	6,383	14,561	16,344	20,927	14,435	0
Non-cash adjustment					0
Cash payments	(15,489)	(16,181)	(4,413)	(10,728)	0	0
Restructuring reserve, ending balance	25,839	34,945	36,565	24,634	14,435	0
Amount expected to be incurred, including charges to date	82,752
Long-lived asset impairments and contract and lease terminations
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	5,537	770	905	1,060	0	0
Charges	(32)	4,903	17	13	22,307	0
Non-cash adjustment					(21,247)
Cash payments	(214)	(136)	(152)	(168)	0	0
Restructuring reserve, ending balance	5,291	5,537	770	905	1,060	0
Amount expected to be incurred, including charges to date	27,208
Other transaction costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	10	493	3,506	2,049	0	0
Charges	7	(47)	795	5,795	4,996	0
Non-cash adjustment					(2,947)
Cash payments	(17)	(436)	(3,808)	(4,338)	0	0
Restructuring reserve, ending balance	0	$ 10	$ 493	$ 3,506	$ 2,049	$ 0
Amount expected to be incurred, including charges to date	$ 11,546