Supplemental Condensed Consolidating Financial Information and Other Collateral-Related Information - Schedule of Condensed Consolidating Balance Sheet (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 566	$ 414	$ 705	$ 373
Accounts receivable, net	5,694	5,208
Inventories	1,279	1,179
Deferred income taxes	366	489
Other	1,025	747
Total current assets	8,930	8,037
Property and equipment, net	14,355	13,619
Investments of insurance subsidiaries	494	448
Investments in and advances to affiliates	165	121
Goodwill and other intangible assets	6,416	5,903	5,539	5,251
Deferred loan costs	219	237
Other	620	466
Total assets	31,199	28,831	28,075
Current liabilities:
Accounts payable	2,035	1,803
Accrued salaries	1,370	1,193
Other accrued expenses	1,737	1,913
Long-term debt due within one year	338	786
Total current liabilities	5,480	5,695
Long-term debt	29,307	27,590
Professional liability risks	1,078	949
Income taxes and other liabilities	1,832	1,525
Total liabilities	37,697	35,759
Stockholders' (deficit) equity attributable to HCA Holdings, Inc.	(7,894)	(8,270)
Noncontrolling interests	1,396	1,342
Total stockholders' deficit	(6,498)	(6,928)	(8,341)	(7,014)
Total liabilities and stockholders' deficit	31,199	28,831
HCA Holdings, Inc. Issuer [Member]
Current assets:
Cash and cash equivalents			22
Deferred income taxes	366	489
Other	118
Total current assets	484	489
Investments in and advances to affiliates	22,293	20,356
Deferred loan costs	26	30
Other	435	250
Total assets	23,238	21,125
Current liabilities:
Accounts payable	1	1
Other accrued expenses	45	272
Total current liabilities	46	273
Long-term debt	2,525	2,525
Intercompany balances	28,008	26,107
Income taxes and other liabilities	553	490
Total liabilities	31,132	29,395
Stockholders' (deficit) equity attributable to HCA Holdings, Inc.	(7,894)	(8,270)
Total stockholders' deficit	(7,894)	(8,270)
Total liabilities and stockholders' deficit	23,238	21,125
HCA Inc. Issuer [Member]
Current assets:
Deferred loan costs	193	207
Total assets	193	207
Current liabilities:
Other accrued expenses	317	353
Long-term debt due within one year	231	702
Total current liabilities	548	1,055
Long-term debt	26,317	24,701
Intercompany balances	(10,261)	(10,513)
Income taxes and other liabilities	487	296
Total liabilities	17,091	15,539
Stockholders' (deficit) equity attributable to HCA Holdings, Inc.	(16,898)	(15,332)
Total stockholders' deficit	(16,898)	(15,332)
Total liabilities and stockholders' deficit	193	207
Subsidiary Guarantors [Member]
Current assets:
Cash and cash equivalents	87	112	383	115
Accounts receivable, net	2,812	2,565
Inventories	756	692
Other	376	301
Total current assets	4,031	3,670
Property and equipment, net	7,871	7,504
Investments in and advances to affiliates	16	13
Goodwill and other intangible assets	1,705	1,695
Other	27	48
Total assets	13,650	12,930
Current liabilities:
Accounts payable	1,272	1,169
Accrued salaries	783	694
Other accrued expenses	517	464
Long-term debt due within one year	56	45
Total current liabilities	2,628	2,372
Long-term debt	185	181
Intercompany balances	(21,582)	(19,428)
Income taxes and other liabilities	605	521
Total liabilities	(18,164)	(16,354)
Stockholders' (deficit) equity attributable to HCA Holdings, Inc.	31,693	29,185
Noncontrolling interests	121	99
Total stockholders' deficit	31,814	29,284
Total liabilities and stockholders' deficit	13,650	12,930
Subsidiary Non-Guarantors [Member]
Current assets:
Cash and cash equivalents	479	302	300	258
Accounts receivable, net	2,882	2,643
Inventories	523	487
Other	531	446
Total current assets	4,415	3,878
Property and equipment, net	6,484	6,115
Investments of insurance subsidiaries	494	448
Investments in and advances to affiliates	149	108
Goodwill and other intangible assets	4,711	4,208
Other	158	168
Total assets	16,411	14,925
Current liabilities:
Accounts payable	762	633
Accrued salaries	587	499
Other accrued expenses	858	824
Long-term debt due within one year	51	39
Total current liabilities	2,258	1,995
Long-term debt	280	183
Intercompany balances	3,835	3,834
Professional liability risks	1,078	949
Income taxes and other liabilities	187	218
Total liabilities	7,638	7,179
Stockholders' (deficit) equity attributable to HCA Holdings, Inc.	7,498	6,503
Noncontrolling interests	1,275	1,243
Total stockholders' deficit	8,773	7,746
Total liabilities and stockholders' deficit	16,411	14,925
Eliminations [Member]
Current assets:
Investments in and advances to affiliates	(22,293)	(20,356)
Total assets	(22,293)	(20,356)
Current liabilities:
Stockholders' (deficit) equity attributable to HCA Holdings, Inc.	(22,293)	(20,356)
Total stockholders' deficit	(22,293)	(20,356)
Total liabilities and stockholders' deficit	$ (22,293)	$ (20,356)