Supplemental Guarantor Information Supplemental Condensed Consolidated Statement of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Net Cash Provided by (Used in) Operating Activities	$ (160,320)	$ (146,694)
Purchases of property and equipment	(145)	(379)
Cash assumed from joint venture at consolidation	995	2,009
Contributions and advances to unconsolidated joint ventures	(21,296)	(7,707)
Contributions to Subsidiaries from Corporate	0	0
Distributions of Equity from Subsidiaries	0	0
Distributions of capital and repayment of advances to unconsolidated joint ventures	13,650	13,977
Interest collected on advances to unconsolidated joint ventures	468
Net Cash Provided by (Used in) Investing Activities	(6,328)	7,900
Proceeds from senior notes	324,465	0
Cash distribution to noncontrolling interest in subsidiary	0	(725)
Borrowings from credit facility	72,000	193,000
Repayments of credit facility	(190,000)	(38,000)
Borrowings from other notes payable	0	343
Repayments of other notes payable	0	(15,636)
Payments of Debt Issuance Costs	(7,382)	(1,064)
Contributions to subsidiaries from corporate	0	0
Distributions to Corporate from Subsidiaries	0	0
Minimum tax withholding paid on behalf of employees for stock awards	(590)	(647)
Excess income tax provision from stock-based compensation	0	(97)
Proceeds from Stock Options Exercised	102	0
Net Cash Provided by (Used in) Financing Activities	198,595	137,174
Cash and Cash Equivalents, Period Increase (Decrease)	31,947	(1,620)
Cash and cash equivalents	62,443	44,254	$ 30,496	$ 45,874
Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities	(135,368)	(122,367)
Purchases of property and equipment	(99)	(204)
Cash assumed from joint venture at consolidation	995	2,009
Contributions and advances to unconsolidated joint ventures	(21,296)	(7,707)
Contributions to Subsidiaries from Corporate	0	0
Distributions of Equity from Subsidiaries	0	725
Distributions of capital and repayment of advances to unconsolidated joint ventures	13,650	13,977
Interest collected on advances to unconsolidated joint ventures	468
Net Cash Provided by (Used in) Investing Activities	(6,282)	8,800
Proceeds from senior notes	0
Cash distribution to noncontrolling interest in subsidiary		0
Borrowings from credit facility	0	0
Repayments of credit facility	0	0
Borrowings from other notes payable		0
Repayments of other notes payable		(13,135)
Payments of Debt Issuance Costs	0	0
Contributions to subsidiaries from corporate	207,849	179,004
Distributions to Corporate from Subsidiaries	(55,180)	(52,800)
Minimum tax withholding paid on behalf of employees for stock awards	0	0
Excess income tax provision from stock-based compensation		0
Proceeds from Stock Options Exercised	0
Net Cash Provided by (Used in) Financing Activities	152,669	113,069
Cash and Cash Equivalents, Period Increase (Decrease)	11,019	(498)
Cash and cash equivalents	24,861	26,642	13,842	27,140
Non-Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities	(65)	3,293
Purchases of property and equipment	0	0
Cash assumed from joint venture at consolidation	0	0
Contributions and advances to unconsolidated joint ventures	0	0
Contributions to Subsidiaries from Corporate	0	0
Distributions of Equity from Subsidiaries	0	0
Distributions of capital and repayment of advances to unconsolidated joint ventures	0	0
Interest collected on advances to unconsolidated joint ventures	0
Net Cash Provided by (Used in) Investing Activities	0	0
Proceeds from senior notes	0
Cash distribution to noncontrolling interest in subsidiary		(725)
Borrowings from credit facility	0	0
Repayments of credit facility	0	0
Borrowings from other notes payable		343
Repayments of other notes payable		(2,501)
Payments of Debt Issuance Costs	0	0
Contributions to subsidiaries from corporate	0	0
Distributions to Corporate from Subsidiaries	0	(725)
Minimum tax withholding paid on behalf of employees for stock awards	0	0
Excess income tax provision from stock-based compensation		0
Proceeds from Stock Options Exercised	0
Net Cash Provided by (Used in) Financing Activities	0	(3,608)
Cash and Cash Equivalents, Period Increase (Decrease)	(65)	(315)
Cash and cash equivalents	204	290	269	605
Parent Company [Member]
Net Cash Provided by (Used in) Operating Activities	(20,466)	(16,393)
Purchases of property and equipment	(46)	(175)
Cash assumed from joint venture at consolidation	0	0
Contributions and advances to unconsolidated joint ventures	0	0
Contributions to Subsidiaries from Corporate	(207,849)	(179,004)
Distributions of Equity from Subsidiaries	50,759	41,573
Distributions of capital and repayment of advances to unconsolidated joint ventures	0	0
Interest collected on advances to unconsolidated joint ventures	0
Net Cash Provided by (Used in) Investing Activities	(157,136)	(137,606)
Proceeds from senior notes	324,465
Cash distribution to noncontrolling interest in subsidiary		0
Borrowings from credit facility	72,000	193,000
Repayments of credit facility	(190,000)	(38,000)
Borrowings from other notes payable		0
Repayments of other notes payable		0
Payments of Debt Issuance Costs	(7,382)	(1,064)
Contributions to subsidiaries from corporate	0	0
Distributions to Corporate from Subsidiaries	0	0
Minimum tax withholding paid on behalf of employees for stock awards	(590)	(647)
Excess income tax provision from stock-based compensation		(97)
Proceeds from Stock Options Exercised	102
Net Cash Provided by (Used in) Financing Activities	198,595	153,192
Cash and Cash Equivalents, Period Increase (Decrease)	20,993	(807)
Cash and cash equivalents	37,378	17,322	16,385	18,129
Consolidation, Eliminations [Member]
Net Cash Provided by (Used in) Operating Activities	(4,421)	(11,227)
Purchases of property and equipment	0	0
Cash assumed from joint venture at consolidation	0	0
Contributions and advances to unconsolidated joint ventures	0	0
Contributions to Subsidiaries from Corporate	207,849	179,004
Distributions of Equity from Subsidiaries	(50,759)	(42,298)
Distributions of capital and repayment of advances to unconsolidated joint ventures	0	0
Interest collected on advances to unconsolidated joint ventures	0
Net Cash Provided by (Used in) Investing Activities	157,090	136,706
Proceeds from senior notes	0
Cash distribution to noncontrolling interest in subsidiary		0
Borrowings from credit facility	0	0
Repayments of credit facility	0	0
Borrowings from other notes payable		0
Repayments of other notes payable		0
Payments of Debt Issuance Costs	0	0
Contributions to subsidiaries from corporate	(207,849)	(179,004)
Distributions to Corporate from Subsidiaries	55,180	53,525
Minimum tax withholding paid on behalf of employees for stock awards	0	0
Excess income tax provision from stock-based compensation		0
Proceeds from Stock Options Exercised	0
Net Cash Provided by (Used in) Financing Activities	(152,669)	(125,479)
Cash and Cash Equivalents, Period Increase (Decrease)	0	0
Cash and cash equivalents	$ 0	$ 0	$ 0	$ 0