Long-Term Incentive Plan (Equity-Based Incentive Compensation Expense) (Details) - Management [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	$ 4,678	$ 4,687	$ 14,737	$ 15,226
G&A Expense [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	4,637	4,643	14,623	15,016
Operating Expenses [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	41	44	114	210
Equity Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	4,678	5,277	14,737	14,725
Liability Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	0	(590)	0	501
Performance Based Awards [Member] | Two Thousand Thirteen Awards [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income		1,083		6,747
Performance Based Awards [Member] | Two Thousand Thirteen Awards [Member] | Equity Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income		1,673		6,246
Performance Based Awards [Member] | Two Thousand Thirteen Awards [Member] | Liability Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income		(590)		501
Performance Based Awards [Member] | Two Thousand Fourteen Awards [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	1,780	1,497	6,168	3,980
Performance Based Awards [Member] | Two Thousand Fourteen Awards [Member] | Equity Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	1,780	1,497	6,168	3,980
Performance Based Awards [Member] | Two Thousand Fourteen Awards [Member] | Liability Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	0	0	0	0
Performance Based Awards [Member] | Two Thousand Fifteen Awards [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	1,208	1,727	3,679	3,687
Performance Based Awards [Member] | Two Thousand Fifteen Awards [Member] | Equity Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	1,208	1,727	3,679	3,687
Performance Based Awards [Member] | Two Thousand Fifteen Awards [Member] | Liability Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	0	0	0	0
Performance Based Awards [Member] | Two Thousand Sixteen Awards [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	1,097		3,240
Performance Based Awards [Member] | Two Thousand Sixteen Awards [Member] | Equity Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	1,097		3,240
Performance Based Awards [Member] | Two Thousand Sixteen Awards [Member] | Liability Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	0		0
Time-Based Awards [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	593	380	1,650	812
Time-Based Awards [Member] | Equity Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	593	380	1,650	812
Time-Based Awards [Member] | Liability Method [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Allocation of LTIP expense on consolidated statements of income	$ 0	$ 0	$ 0	$ 0