Long-Term Debt (Boyd Bank Credit Facility Narrative) (Details) (USD $)		6 Months Ended										6 Months Ended															0 Months Ended
	Dec. 03, 2010	Jun. 30, 2012 Minimum	Nov. 02, 2011 Base Rate	Nov. 02, 2011 Effective Eurodollar Rate	Jun. 30, 2012 Bank Credit Facility	Dec. 03, 2010 Bank Credit Facility Initial Term Loan	Nov. 02, 2011 Bank Credit Facility Incremental Term Loan	Jun. 30, 2012 Parent Bank Credit Facility	Dec. 31, 2011 Parent Bank Credit Facility	Nov. 02, 2011 Parent Bank Credit Facility	Dec. 03, 2010 Parent Bank Credit Facility	Jun. 30, 2012 Parent Bank Credit Facility Maximum	Jun. 30, 2012 Parent Bank Credit Facility Minimum	Jun. 30, 2012 Parent Bank Credit Facility Base Rate Federal Funds Rate	Jun. 30, 2012 Parent Bank Credit Facility Base Rate One-month Eurodollar	Jun. 30, 2012 Parent Bank Credit Facility Extended Revolving Facility	Dec. 31, 2011 Parent Bank Credit Facility Extended Revolving Facility	Jun. 30, 2012 Parent Bank Credit Facility Extended Revolving Facility LIBOR Maximum	Jun. 30, 2012 Parent Bank Credit Facility Extended Revolving Facility LIBOR Minimum	Jun. 30, 2012 Parent Bank Credit Facility Extended Revolving Facility Base Rate Maximum	Jun. 30, 2012 Parent Bank Credit Facility Extended Revolving Facility Base Rate Minimum	Jun. 30, 2012 Parent Bank Credit Facility Initial Term Loan	Dec. 31, 2011 Parent Bank Credit Facility Initial Term Loan	Jun. 30, 2012 Parent Bank Credit Facility Incremental Term Loan	Dec. 31, 2011 Parent Bank Credit Facility Incremental Term Loan	Nov. 02, 2011 Parent Bank Credit Facility Incremental Term Loan	Jun. 08, 2012 Parent Bank Credit Facility Increased Revolving Commitment	May 31, 2012 Parent Bank Credit Facility Increased Revolving Commitment	May 30, 2012 Parent Bank Credit Facility Increased Revolving Commitment	Jun. 30, 2012 Parent Letter of Credit	Jun. 30, 2012 Former Credit Facility Parent Bank Credit Facility	Dec. 02, 2010 Former Credit Facility Parent Bank Credit Facility	Dec. 03, 2010 Former Credit Facility Parent Bank Credit Facility Maximum	Jun. 30, 2012 Former Credit Facility Parent Bank Credit Facility Extended Revolving Facility	Jun. 30, 2012 Former Credit Facility Parent Bank Credit Facility Initial Term Loan	Jun. 30, 2012 Former Credit Facility Parent Bank Credit Facility Incremental Term Loan	Jun. 30, 2012 Non-extending Lenders Parent Bank Credit Facility LIBOR Maximum	Jun. 30, 2012 Non-extending Lenders Parent Bank Credit Facility LIBOR Minimum	Jun. 30, 2012 Non-extending Lenders Parent Bank Credit Facility Base Rate Maximum	Jun. 30, 2012 Non-extending Lenders Parent Bank Credit Facility Base Rate Minimum
Line of Credit Facility [Line Items]
Maturity term	5 years
Blended interest rate at period end								4.30%	4.20%
Amount outstanding, gross								$ 1,450,000,000
Amount outstanding								1,439,263,000	1,621,715,000							620,000,000	807,000,000					462,500,000	475,000,000	331,713,000	338,965,000				150,000,000	14,500,000
Remaining borrowing capacity								300,405,000								300,405,000						0		0
Extended Revolving Facility:
Repayment of line of credit																											150,000,000
Percentage reduction of commitments by each lender																																	50.00%
Line of credit, maximum borrowing capacity											1,500,000,000																				1,460,000,000	3,000,000,000		960,000,000	500,000,000	0
Additional available borrowing capacity											500,000,000
Applicable margin			3.75%	4.75%														3.50%	2.50%	2.50%	1.50%																1.625%	0.625%	0.375%	0.00%
Commitment fee percentage on unused portion of credit facility												0.50%	0.25%
Interest rate, basis spread on fixed portion of reference rate														0.50%	1.00%
Term Loans:
Face amount						500,000,000	350,000,000
Annual principal payment, percent of face amount						5.00%	5.00%
Covenants:
Minimum consolidated interest coverage ratio required										2
Maximum total leverage ratio allowed					7.50
Maximum total leverage ratio allowed, periodic increment					0.25
Future maximum total leverage ratio allowed					5.50
Maximum secured leverage ratio allowed					4.25
Maximum secured leverage ratio allowed, periodic increment					0.25
Future maximum secured leverage ratio allowed					3.25
Actual consolidated interest coverage ratio					2.55
Actual total leverage ratio					7.05
Actual secured leverage ratio					3.69
Total leverage ratio covenant sensitivity, % decline in consolidated EBITDA which would trigger noncompliance		9.20%
Secured leverage ratio covenant sensitivity, % decline in consolidated EBITDA which would trigger noncompliance		18.10%
Interest coverage ratio covenant sensitivity, % decline in consolidated EBITDA which would trigger noncompliance		21.40%
Debt Financing Costs [Abstract]
Deferred finance costs											$ 20,600,000															$ 13,900,000		$ 1,500,000