Schedule II - Condensed Balance Sheets Parent Company (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$ 1,006,138	$ 1,027,321	$ 1,190,080	$ 834,837
Income taxes receivable	67,970	1,067
Deferred income taxes	228,086	237,649
Other assets	202,460	180,777
Total assets	8,831,777	8,236,715	7,647,889
LIABILITIES AND EQUITY
Accounts payable and other accrued liabilities	793,955	876,087
Income taxes payable	10,376	7,576
Deferred income taxes	450,207	343,682
Notes and contracts payable	736,693	581,052
Total liabilities	5,817,428	5,483,592
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.00001 par value; Authorized—500 shares; Outstanding—none
Common stock, $0.00001 par value; Authorized—300,000 shares; Outstanding-[0] shares and 109,098 shares	1	1
Additional paid-in capital	2,191,756	2,150,813
Retained earnings	1,046,822	838,149
Accumulated other comprehensive loss	(230,400)	(239,003)	(199,106)
Total stockholders’ equity	3,008,179	2,749,960
Noncontrolling interests	6,170	3,163
Total equity	3,014,349	2,753,123	2,567,502	2,447,701
Total liabilities and equity	8,831,777	8,236,715
Parent Company
ASSETS
Cash and cash equivalents	221,519	289,791	$ 328,949	$ 221,666
Due from subsidiaries, net	77,557	21,430
Income taxes receivable	67,970	1,067
Investment in subsidiaries	3,897,995	3,478,704
Deferred income taxes	20,037	22,020
Other assets	85,709	92,633
Total assets	4,370,787	3,905,645
LIABILITIES AND EQUITY
Accounts payable and other accrued liabilities	39,069	58,483
Pension costs and other retirement plans	359,057	413,206
Income taxes payable	10,376	7,576
Deferred income taxes	242,158	128,053
Notes and contracts payable	705,778	545,204
Total liabilities	1,356,438	1,152,522
Commitments and contingencies	0	0
Stockholders’ equity:
Preferred stock, $0.00001 par value; Authorized—500 shares; Outstanding—none	0	0
Common stock, $0.00001 par value; Authorized—300,000 shares; Outstanding-[0] shares and 109,098 shares	1	1
Additional paid-in capital	2,191,756	2,150,813
Retained earnings	1,046,822	838,149
Accumulated other comprehensive loss	(230,400)	(239,003)
Total stockholders’ equity	3,008,179	2,749,960
Noncontrolling interests	6,170	3,163
Total equity	3,014,349	2,753,123
Total liabilities and equity	$ 4,370,787	$ 3,905,645