Fair Value Measurements (Carrying Amounts and Estimated Fair Values of Financial Instruments Not Measured at Fair Value) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Carrying Amount
Assets:
Cash and cash equivalents	$ 1,006,138	$ 1,027,321
Deposits with banks	21,222	23,224
Notes receivable, net	7,799	5,866
Liabilities:
Deposits	2,779,478	2,699,015
Notes and contracts payable	736,693	581,052
Estimated Fair Value
Assets:
Cash and cash equivalents	1,006,138	1,027,321
Deposits with banks	21,176	23,211
Notes receivable, net	7,542	5,791
Liabilities:
Deposits	2,779,478	2,699,015
Notes and contracts payable	734,812	590,970
Estimated Fair Value | Level 1
Assets:
Cash and cash equivalents	1,006,138	1,027,321
Deposits with banks	1,017	1,103
Notes receivable, net	0	0
Liabilities:
Deposits	2,779,478	2,699,015
Notes and contracts payable	0	0
Estimated Fair Value | Level 2
Assets:
Cash and cash equivalents	0	0
Deposits with banks	20,159	22,108
Notes receivable, net	0	0
Liabilities:
Deposits	0	0
Notes and contracts payable	729,658	583,893
Estimated Fair Value | Level 3
Assets:
Cash and cash equivalents	0	0
Deposits with banks	0	0
Notes receivable, net	7,542	5,791
Liabilities:
Deposits	0	0
Notes and contracts payable	$ 5,154	$ 7,077