New Accounting Pronouncements - Summary of Cumulative Effects of Changes in Consolidated Condensed Balance Sheet for Adoption of ASU 2016-02 (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Prepaid expenses and other assets	$ 39,884		$ 54,271
Assets held for sale	6,742		69,699
Operating lease right-of-use assets	12,136
Liabilities held for sale	6,742		13,062
Deferred tax liabilities	1,142		1,177
Non-current lease liabilities	7,391
Accumulated earnings	$ 391,278		$ 363,965
ASU 2016-02
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Prepaid expenses and other assets		$ 54,197
Assets held for sale		73,826
Operating lease right-of-use assets		13,019
Liabilities held for sale		17,198
Deferred tax liabilities		1,291
Non-current lease liabilities		12,561
Accumulated earnings		364,226
Adjustments Due to Adoption of ASU 2016-02 | ASU 2016-02
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Prepaid expenses and other assets		(74)
Assets held for sale		4,127
Operating lease right-of-use assets		13,019
Liabilities held for sale		4,136
Deferred tax liabilities		114
Non-current lease liabilities		12,561
Accumulated earnings		$ 261