Segment information - Selected Statement of Operations and Income (Loss) Information Related to Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 509,906	$ 559,508	$ 472,075	$ 398,519	$ 469,934	$ 507,640	$ 492,869	$ 437,229	$ 1,940,008	$ 1,907,672	$ 1,955,724
Depreciation and amortization									22,526	24,932	25,878
Income (loss) before taxes and noncontrolling interest									116,967	72,529	75,067
Title segment
Segment Reporting Information [Line Items]
Revenues									1,857,048	1,855,706	1,899,462
Depreciation and amortization									19,971	21,449	21,384
Income (loss) before taxes and noncontrolling interest									108,459	108,314	103,361
Ancillary services and corporate segment
Segment Reporting Information [Line Items]
Revenues									82,960	51,966	56,262
Depreciation and amortization									2,555	3,483	4,494
Income (loss) before taxes and noncontrolling interest									$ 8,508	$ (35,785)	$ (28,294)