Summary of Significant Accounting Policies (Schedule Of The Company's Interests In Land Option Agreements) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Land under option agreement [Line Items]
Deposits and Pre-acquisition Costs	$ 218,568	$ 207,987
Remaining Purchase Price	2,602,410	2,462,579
Other Land Option Agreements Member
Land under option agreement [Line Items]
Deposits and Pre-acquisition Costs	127,851	129,098
Remaining Purchase Price	1,522,903	1,485,099
Consolidated and Unconsolidated VIEs [Member]
Land under option agreement [Line Items]
Deposits and Pre-acquisition Costs	90,717	78,889
Remaining Purchase Price	$ 1,079,507	$ 977,480