Long-Term Incentive Plan (Equity-Based Incentive Compensation Expense) (Details) - Management [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	$ 24,245	$ 27,284	$ 24,083
G&A Expense [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	23,937	26,700	23,264
Operating Expenses [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	308	584	819
Time-Based Awards [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	1,199	1,624	575
2010 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	194
2011 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	9,639
2012 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	8,314	7,498
2013 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	10,658	10,852	6,177
2014 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	7,471	6,494	0
2015 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	4,917	0	0
Liability Method [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	1,997	7,321	8,551
Liability Method [Member] | 2010 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	73
Liability Method [Member] | 2011 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	4,280
Liability Method [Member] | 2012 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	3,896	2,747
Liability Method [Member] | 2013 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	1,997	3,425	1,451
Liability Method [Member] | 2014 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	0
Liability Method [Member] | 2015 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	0
Equity Method [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	22,248	19,963	15,532
Equity Method [Member] | Time-Based Awards [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	1,199	1,624	575
Equity Method [Member] | 2010 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	121
Equity Method [Member] | 2011 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	0	5,359
Equity Method [Member] | 2012 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	0	4,418	4,751
Equity Method [Member] | 2013 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	8,661	7,427	4,726
Equity Method [Member] | 2014 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	7,471	6,494	0
Equity Method [Member] | 2015 Awards [Member] | Performance Shares [Member]
Long Term Incentive Plan [Line Items]
Allocation of LTIP expense on Consolidated Statements of Income	$ 4,917	$ 0	$ 0