Fair Value Measurements (Schedule of Fair Value Disclosures) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Tax Increment Revenue Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit loss recognized		$ 31,000	$ 31,000
Investments, Held To Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross unrealized gain (loss)		3	(8)
Carrying Value [Member] | Fixed-Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt		1,919,052	1,651,959
Carrying Value [Member] | Variable-Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt		168,905	286,229
Carrying Value [Member] | Tax Increment Revenue Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	[1]	25,377	25,392
Carrying Value [Member] | Investments, Held To Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	[2]	2,000	2,750
Fair Value [Member] | Fair Value Using Significant Other Observable Inputs (Level 2) [Member] | Investments, Held To Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	[2]	2,003	2,742
Fair Value [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member] | Fixed-Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt		1,942,612	1,719,775
Fair Value [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member] | Variable-Rate Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt		174,616	292,972
Fair Value [Member] | Fair Value Using Significant Unobservable Inputs (Level 3) [Member] | Tax Increment Revenue Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	[1]	$ 25,377	$ 25,392

[1] At June 30, 2015 and December 31, 2014, the credit loss balance on our tax increment revenue bonds was $31.0 million.

[2] Investments held to maturity are recorded at cost and have a gross unrealized gain of $3 thousand as of June 30, 2015 and an $8 thousand gross unrealized loss as of December 31, 2014.