Summary of Significant Accounting Policies (Cash and Cash Equivalents) - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 162,344	$ 155,315	$ 128,771	$ 65,427	$ 135,534	$ 190,515
Cash equivalents	5,700		1,400
Investments in Joint Ventures [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	17,800		24,900
Domestic Joint Ventures [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	13,400		11,900
Domestic Bank Accounts [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	13,400		16,100
Foreign Bank Accounts [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 148,900		$ 112,700