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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 469,934	$ 507,640	$ 492,869	$ 437,229	$ 525,664	$ 501,569	$ 485,452	$ 443,039	$ 1,907,672	$ 1,955,724	$ 2,006,640
Depreciation and amortization									24,932	25,878	30,044
Income (loss) before taxes and noncontrolling interest									72,529	75,067	88,026
Title segment
Segment Reporting Information [Line Items]
Revenues									1,855,706	1,899,462	1,922,422
Depreciation and amortization									21,449	21,384	21,176
Income (loss) before taxes and noncontrolling interest									108,314	103,361	139,083
Ancillary services and corporate segment
Segment Reporting Information [Line Items]
Revenues									51,966	56,262	84,218
Depreciation and amortization									3,483	4,494	8,868
Income (loss) before taxes and noncontrolling interest									$ (35,785)	$ (28,294)	$ (51,057)