Debt Debt (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 15, 2017 USD ($)	Dec. 31, 2016 USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date	Jul. 18, 2021
Minimum Tangible Net Worth	$ 487,200
Leverage ratio	60.00%
Notes payable bank - homebuilding operations	$ 0		$ 40,300
Debt Instrument, Unused Borrowing Capacity, Amount	512,920
letters of credit outstanding under credit facility	49,049
Maximum borrowing availability subject to limit	426,000
Letters of Credit Outstanding Under Letter of Credit Facilities	604		624
Aggregate Capacity of Secured Letters of Credit under Credit Facility	1,000		2,000
Restricted Cash for Secured Letter of Credit Agreements	610		$ 630
First Amendment to New Unsecured Credit Facility [Member]
Line of Credit Facility [Line Items]
Sub-limit for letters of credit	125,000
Line of Credit Facility, Maximum Borrowing Capacity	$ 500,000
Maximum [Member] | First Amendment to New Unsecured Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis Points Spread on Variable Rate - Credit Facility	250
Consolidated EBITDA [Member]
Line of Credit Facility [Line Items]
Interest Coverage Ratio	1.50
Consolidated Interest Incurred [Member]
Line of Credit Facility [Line Items]
Interest Coverage Ratio	1.00
2025 Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	$ 250,000
Debt Instrument, Interest Rate, Stated Percentage	5.625%
2018 Convertible Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.00%
Convertible Subordinated Debt	$ 86,250
2021 Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Face Amount	$ 300,000
Debt Instrument, Interest Rate, Stated Percentage	6.75%
2017 Convertible Senior Notes [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.25%
Convertible Subordinated Debt		$ 57,500