Fair Value Measurements (Carrying Amounts and Estimated Fair Values of Financial Instruments Not Measured at Fair Value) (Detail) - USD ($)
$ in Thousands
Mar. 31, 2016
Dec. 31, 2015
Carrying Amount    
Assets:    
Cash and cash equivalents $ 975,883 $ 1,027,321
Deposits with banks 22,883 23,224
Notes receivable, net 7,615 5,866
Liabilities:    
Deposits 2,758,932 2,699,015
Notes and contracts payable 580,467 581,052
Estimated Fair Value    
Assets:    
Cash and cash equivalents 975,883 1,027,321
Deposits with banks 22,891 23,211
Notes receivable, net 6,860 5,791
Liabilities:    
Deposits 2,758,932 2,699,015
Notes and contracts payable 595,941 590,970
Estimated Fair Value | Level 1    
Assets:    
Cash and cash equivalents 975,883 1,027,321
Deposits with banks 1,158 1,103
Liabilities:    
Deposits 2,758,932 2,699,015
Estimated Fair Value | Level 2    
Assets:    
Deposits with banks 21,733 22,108
Liabilities:    
Notes and contracts payable 588,835 583,893
Estimated Fair Value | Level 3    
Assets:    
Notes receivable, net 6,860 5,791
Liabilities:    
Notes and contracts payable $ 7,106 $ 7,077