Fair Value Measurements (Carrying Amounts and Estimated Fair Values of Financial Instruments Not Measured at Fair Value) (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Carrying Amount
Assets:
Cash and cash equivalents	$ 1,047,467	$ 1,006,138
Deposits with banks	21,974	21,222
Notes receivable, net	6,796	7,799
Liabilities:
Deposits	2,882,812	2,779,478
Notes and contracts payable	735,549	736,693
Estimated Fair Value
Assets:
Cash and cash equivalents	1,047,467	1,006,138
Deposits with banks	21,919	21,176
Notes receivable, net	6,558	7,542
Liabilities:
Deposits	2,882,812	2,779,478
Notes and contracts payable	746,880	734,812
Estimated Fair Value | Level 1
Assets:
Cash and cash equivalents	1,047,467	1,006,138
Deposits with banks	547	1,017
Notes receivable, net	0	0
Liabilities:
Deposits	2,882,812	2,779,478
Notes and contracts payable	0	0
Estimated Fair Value | Level 2
Assets:
Cash and cash equivalents	0	0
Deposits with banks	21,372	20,159
Notes receivable, net	0	0
Liabilities:
Deposits	0	0
Notes and contracts payable	742,243	729,658
Estimated Fair Value | Level 3
Assets:
Cash and cash equivalents	0	0
Deposits with banks	0	0
Notes receivable, net	6,558	7,542
Liabilities:
Deposits	0	0
Notes and contracts payable	$ 4,637	$ 5,154