Reorganization (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Mar. 31, 2015	Jun. 30, 2015
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 37,828	$ 29,045	$ 17,544	$ 0	$ 0
Charges	19,417	17,156	26,735	0	41,738
Non-cash adjustment					(24,194)
Cash payments	(16,753)	(8,373)	(15,234)	0	0
Restructuring reserve, ending balance	40,492	37,828	29,045	0	17,544
Amount expected to be incurred, including charges to date	121,447
Premium deficiency reserves
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	78,047
Charges	13,527
Restructuring reserve, ending balance	91,574	78,047
Premium deficiency charges	182,627
Amount expected to be incurred, including charges to date	304,074
Severance and retention
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	36,565	24,634	14,435	0	0
Charges	14,561	16,344	20,927	0	14,435
Non-cash adjustment					0
Cash payments	(16,181)	(4,413)	(10,728)	0	0
Restructuring reserve, ending balance	34,945	36,565	24,634	0	14,435
Amount expected to be incurred, including charges to date	82,668
Long-lived asset impairments and contract and lease terminations
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	770	905	1,060	0	0
Charges	4,903	17	13	0	22,307
Non-cash adjustment					(21,247)
Cash payments	(136)	(152)	(168)	0	0
Restructuring reserve, ending balance	5,537	770	905	0	1,060
Amount expected to be incurred, including charges to date	27,240
Other transaction costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	493	3,506	2,049	0	0
Charges	(47)	795	5,795	0	4,996
Non-cash adjustment					(2,947)
Cash payments	(436)	(3,808)	(4,338)	0	0
Restructuring reserve, ending balance	10	$ 493	$ 3,506	$ 0	$ 2,049
Amount expected to be incurred, including charges to date	$ 11,539