Condensed consolidating financial information - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Apr. 15, 2014	Dec. 31, 2013	Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 63,364	$ 63,807		$ 98,294	$ 135,366
Cash and securities segregated for regulatory and other purposes	0	18,594
Deposits with clearing organizations	49,490	36,510
Receivable from brokers, dealers and clearing organizations	360,913	314,475
Receivable from customers, net of allowance for credit losses	840,355	864,189
Income tax receivable	10,937	4,240
Securities purchased under agreements to resell	206,499	251,606
Securities owned	735,393	843,155
Notes receivable, net of accumulated amortization and allowance for uncollectibles	32,849	34,932
Office facilities, net of accumulated depreciation	28,290	29,589
Loans held for sale	60,234	19,243
Mortgage servicing rights	28,168	30,140		28,879
Subordinated loan receivable	0	0
Intangible assets	31,700	31,700
Goodwill	137,889	137,889
Other assets	106,883	107,386
Deferred tax assets	0	0
Investment in subsidiaries	0	0
Intercompany receivables	0	0
Total assets	2,692,964	2,787,455
Liabilities
Drafts payable	48,011	35,373
Bank call loans	100,200	59,400
Payable to brokers, dealers and clearing organizations	164,546	257,161
Payable to customers	594,833	652,256
Securities sold under agreements to repurchase	651,445	687,440
Securities sold, but not yet purchased, at fair value	126,493	92,510
Accrued compensation	150,898	165,134
Accounts payable and other liabilities	164,783	141,352
Income tax payable	0	0
Senior secured notes	150,000	150,000	$ 150,000
Subordinated indebtedness	0	0
Deferred tax liabilities	16,673	13,097
Intercompany payables	0	0
Total liabilities	2,167,882	2,253,723
Stockholders’ equity
Stockholders' equity attributable to Oppenheimer Holdings Inc.	518,058	527,644
Noncontrolling interest	7,024	6,088
Total stockholders’ equity	525,082	533,732		527,871
Total liabilities and stockholders’ equity	2,692,964	2,787,455
Allowance for credit losses	2,545	2,427
Amounts pledged	546,334	518,123
Notes receivable, net accumulated amortization	54,919	42,211
Notes receivable, net allowance for uncollectibles	8,444	8,606
Net accumulated depreciation	104,961	103,547
Reportable Legal Entities | Parent
ASSETS
Cash and cash equivalents	907	439		448	35
Cash and securities segregated for regulatory and other purposes		0
Deposits with clearing organizations	0	0
Receivable from brokers, dealers and clearing organizations	0	0
Receivable from customers, net of allowance for credit losses	0	0
Income tax receivable	33,801	28,070
Securities purchased under agreements to resell	0	0
Securities owned	0	0
Notes receivable, net of accumulated amortization and allowance for uncollectibles	0	0
Office facilities, net of accumulated depreciation	0	0
Loans held for sale	0	0
Mortgage servicing rights	0	0
Subordinated loan receivable	0	0
Intangible assets	0	0
Goodwill	0	0
Other assets	1,201	1,686
Deferred tax assets	317	18
Investment in subsidiaries	577,320	565,257
Intercompany receivables	60,187	87,442
Total assets	673,733	682,912
Liabilities
Drafts payable	0	0
Bank call loans	0	0
Payable to brokers, dealers and clearing organizations	0	0
Payable to customers	0	0
Securities sold under agreements to repurchase	0	0
Securities sold, but not yet purchased, at fair value	0	0
Accrued compensation	0	0
Accounts payable and other liabilities	3,235	2,828
Income tax payable	2,440	2,440
Senior secured notes	150,000	150,000
Subordinated indebtedness	0	0
Deferred tax liabilities	0	0
Intercompany payables	0	0
Total liabilities	155,675	155,268
Stockholders’ equity
Stockholders' equity attributable to Oppenheimer Holdings Inc.	518,058	527,644
Noncontrolling interest	0	0
Total stockholders’ equity	518,058	527,644
Total liabilities and stockholders’ equity	673,733	682,912
Reportable Legal Entities | Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	2,586	1,557		30,901	40,658
Cash and securities segregated for regulatory and other purposes		0
Deposits with clearing organizations	0	0
Receivable from brokers, dealers and clearing organizations	0	0
Receivable from customers, net of allowance for credit losses	0	0
Income tax receivable	27,536	27,304
Securities purchased under agreements to resell	0	0
Securities owned	1,183	5,806
Notes receivable, net of accumulated amortization and allowance for uncollectibles	0	0
Office facilities, net of accumulated depreciation	20,793	20,181
Loans held for sale	0	0
Mortgage servicing rights	0	0
Subordinated loan receivable	112,558	112,558
Intangible assets	0	0
Goodwill	0	0
Other assets	3,224	3,803
Deferred tax assets	330	309
Investment in subsidiaries	532,651	544,576
Intercompany receivables	13,185	0
Total assets	714,046	716,094
Liabilities
Drafts payable	0	0
Bank call loans	0	0
Payable to brokers, dealers and clearing organizations	0	0
Payable to customers	0	0
Securities sold under agreements to repurchase	0	0
Securities sold, but not yet purchased, at fair value	0	0
Accrued compensation	0	0
Accounts payable and other liabilities	35,812	35,800
Income tax payable	22,189	22,189
Senior secured notes	0	0
Subordinated indebtedness	0	0
Deferred tax liabilities	0	88
Intercompany payables	62,204	76,492
Total liabilities	120,205	134,569
Stockholders’ equity
Stockholders' equity attributable to Oppenheimer Holdings Inc.	593,841	581,525
Noncontrolling interest	0	0
Total stockholders’ equity	593,841	581,525
Total liabilities and stockholders’ equity	714,046	716,094
Reportable Legal Entities | Non-Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	59,871	61,811		66,945	94,673
Cash and securities segregated for regulatory and other purposes		18,594
Deposits with clearing organizations	49,490	36,510
Receivable from brokers, dealers and clearing organizations	360,913	314,475
Receivable from customers, net of allowance for credit losses	840,355	864,189
Income tax receivable	0	0
Securities purchased under agreements to resell	206,499	251,606
Securities owned	734,210	837,349
Notes receivable, net of accumulated amortization and allowance for uncollectibles	32,849	34,932
Office facilities, net of accumulated depreciation	7,497	9,408
Loans held for sale	60,234	19,243
Mortgage servicing rights	28,168	30,140
Subordinated loan receivable	0	0
Intangible assets	31,700	31,700
Goodwill	137,889	137,889
Other assets	102,458	101,897
Deferred tax assets	29,900	27,973
Investment in subsidiaries	0	0
Intercompany receivables	0	0
Total assets	2,682,033	2,777,716
Liabilities
Drafts payable	48,011	35,373
Bank call loans	100,200	59,400
Payable to brokers, dealers and clearing organizations	164,546	257,161
Payable to customers	594,833	652,256
Securities sold under agreements to repurchase	651,445	687,440
Securities sold, but not yet purchased, at fair value	126,493	92,510
Accrued compensation	150,898	165,134
Accounts payable and other liabilities	125,736	102,724
Income tax payable	25,771	26,505
Senior secured notes	0	0
Subordinated indebtedness	112,558	112,558
Deferred tax liabilities	47,220	41,309
Intercompany payables	11,168	10,950
Total liabilities	2,158,879	2,243,320
Stockholders’ equity
Stockholders' equity attributable to Oppenheimer Holdings Inc.	516,130	528,308
Noncontrolling interest	7,024	6,088
Total stockholders’ equity	523,154	534,396
Total liabilities and stockholders’ equity	2,682,033	2,777,716
Eliminations
ASSETS
Cash and cash equivalents	0	0		$ 0	$ 0
Cash and securities segregated for regulatory and other purposes		0
Deposits with clearing organizations	0	0
Receivable from brokers, dealers and clearing organizations	0	0
Receivable from customers, net of allowance for credit losses	0	0
Income tax receivable	(50,400)	(51,134)
Securities purchased under agreements to resell	0	0
Securities owned	0	0
Notes receivable, net of accumulated amortization and allowance for uncollectibles	0	0
Office facilities, net of accumulated depreciation	0	0
Loans held for sale	0	0
Mortgage servicing rights	0	0
Subordinated loan receivable	(112,558)	(112,558)
Intangible assets	0	0
Goodwill	0	0
Other assets	0	0
Deferred tax assets	(30,547)	(28,300)
Investment in subsidiaries	(1,109,971)	(1,109,833)
Intercompany receivables	(73,372)	(87,442)
Total assets	(1,376,848)	(1,389,267)
Liabilities
Drafts payable	0	0
Bank call loans	0	0
Payable to brokers, dealers and clearing organizations	0	0
Payable to customers	0	0
Securities sold under agreements to repurchase	0	0
Securities sold, but not yet purchased, at fair value	0	0
Accrued compensation	0	0
Accounts payable and other liabilities	0	0
Income tax payable	(50,400)	(51,134)
Senior secured notes	0	0
Subordinated indebtedness	(112,558)	(112,558)
Deferred tax liabilities	(30,547)	(28,300)
Intercompany payables	(73,372)	(87,442)
Total liabilities	(266,877)	(279,434)
Stockholders’ equity
Stockholders' equity attributable to Oppenheimer Holdings Inc.	(1,109,971)	(1,109,833)
Noncontrolling interest	0	0
Total stockholders’ equity	(1,109,971)	(1,109,833)
Total liabilities and stockholders’ equity	$ (1,376,848)	$ (1,389,267)