Consolidation of Certain Interests (Computation of Bargain Purchase Gain) (Details) (Borgata, USD $)	3 Months Ended
Mar. 31, 2011	Jun. 30, 2012
Borgata
Business Acquisition [Line Items]
Component of fair value of controlling interest, control premium	$ 72,400,000
Control premium, percentage applied to enterprise value members' equity	10.00%
Noncontrolling interest, ownership percentage by parent		50.00%
Fair value of controlling equity interest	397,931,000
Carrying amount of equity investment in Borgata	397,622,000
Bargain purchase gain	$ 309,000

In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 36, 37, 38

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6571-128477

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6527-128477

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (f)(1)

-URI http://asc.fasb.org/extlink&oid=7488404&loc=d3e6927-128479

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph o(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6393-128476

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6396-128476

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6387-128476

+ Details