Goodwill and Intangible Assets - Additional information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill And Intangible Assets [Line Items]
Identifiable and amortizable intangible assets	$ 97,000	$ 112,000
Amount of goodwill	136,000	136,000
Accumulated amortization, net	143,000	128,000
Amortization expense	15,000	15,000	15,000
Remaining weighted-average amortization period for intangible assets	9 years
Amortization expense, 2014	15,000
Amortization expense, 2015	15,000
Amortization expense, 2016	15,000
Provider Network [Member]
Goodwill And Intangible Assets [Line Items]
Identifiable and amortizable intangible assets	63,000
Amortization period of intangible asset	20 years
Membership [Member]
Goodwill And Intangible Assets [Line Items]
Identifiable and amortizable intangible assets	$ 34,000
Amortization period of intangible asset	11 years