Fair Value Measurements (Fair Value Balance Sheet Grouping) (Details) (Fair Value, Measurements, Nonrecurring, USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	$ 3,581,628	$ 3,431,939
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	3,534,176	3,390,456
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	3,525,787	3,062,901
Boyd | Bank Credit Facility | Bank Credit Facility | Fair Value, Inputs, Level 2 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	1,448,800	1,632,750
Boyd | Bank Credit Facility | Bank Credit Facility | Fair Value, Inputs, Level 2 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	1,431,325	1,621,715
Boyd | Bank Credit Facility | Bank Credit Facility | Fair Value, Inputs, Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	1,404,016	1,388,630
Boyd | 9.125% Senior Notes Due 2018 | Senior Notes | Fair Value, Inputs, Level 1 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	500,000	500,000
Boyd | 9.125% Senior Notes Due 2018 | Senior Notes | Fair Value, Inputs, Level 1 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	500,000	491,444
Boyd | 9.125% Senior Notes Due 2018 | Senior Notes | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	522,500	471,000
Boyd | 9.00% Senior Notes Due 2020 | Senior Notes | Fair Value, Inputs, Level 1 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	350,000
Boyd | 9.00% Senior Notes Due 2020 | Senior Notes | Fair Value, Inputs, Level 1 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	340,103
Boyd | 9.00% Senior Notes Due 2020 | Senior Notes | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	352,625
Boyd | 6.75% Senior Subordinated Notes Due 2014 | Senior Subordinated Notes | Fair Value, Inputs, Level 1 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	215,668	215,668
Boyd | 6.75% Senior Subordinated Notes Due 2014 | Senior Subordinated Notes | Fair Value, Inputs, Level 1 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	215,668	215,668
Boyd | 6.75% Senior Subordinated Notes Due 2014 | Senior Subordinated Notes | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	216,207	208,120
Boyd | 7.125% Senior Subordinated Notes Due 2016 | Senior Subordinated Notes | Fair Value, Inputs, Level 1 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	240,750	240,750
Boyd | 7.125% Senior Subordinated Notes Due 2016 | Senior Subordinated Notes | Fair Value, Inputs, Level 1 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	240,750	240,750
Boyd | 7.125% Senior Subordinated Notes Due 2016 | Senior Subordinated Notes | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	235,935	208,249
Boyd | Other | Fixed Rate Debt | Fair Value, Inputs, Level 3 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	10,710	11,071
Boyd | Other | Fixed Rate Debt | Fair Value, Inputs, Level 3 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	10,710	11,071
Boyd | Other | Fixed Rate Debt | Fair Value, Inputs, Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	10,175	10,517
Borgata | Bank Credit Facility | Bank Credit Facility | Fair Value, Inputs, Level 2 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	24,200	40,200
Borgata | Bank Credit Facility | Bank Credit Facility | Fair Value, Inputs, Level 2 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	24,200	40,200
Borgata | Bank Credit Facility | Bank Credit Facility | Fair Value, Inputs, Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	24,200	40,200
Borgata | 9.50% Senior Secured Notes Due 2015 | Secured Debt | Fair Value, Inputs, Level 1 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	398,000	398,000
Borgata | 9.50% Senior Secured Notes Due 2015 | Secured Debt | Fair Value, Inputs, Level 1 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	388,266	387,049
Borgata | 9.50% Senior Secured Notes Due 2015 | Secured Debt | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	390,239	378,100
Borgata | 9.875% Senior Secured Notes Due 2018 | Secured Debt | Fair Value, Inputs, Level 1 | Outstanding Face Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	393,500	393,500
Borgata | 9.875% Senior Secured Notes Due 2018 | Secured Debt | Fair Value, Inputs, Level 1 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	383,154	382,559
Borgata | 9.875% Senior Secured Notes Due 2018 | Secured Debt | Fair Value, Inputs, Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument, fair value disclosure	$ 369,890	$ 358,085