Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019	Jul. 31, 2018
Assets:
Total assets measured at fair value	$ 76,155	$ 72,607	$ 40,736
Liabilities:
Total liabilities measured at fair value	44,269	55,044	39,451
Level 1
Assets:
Total assets measured at fair value	43,771	39,362	40,575
Liabilities:
Total liabilities measured at fair value	42,298	38,170	38,970
Level 2
Assets:
Total assets measured at fair value	140	22	161
Liabilities:
Total liabilities measured at fair value	71	156	481
Level 3
Assets:
Total assets measured at fair value	32,244	33,223	0
Liabilities:
Total liabilities measured at fair value	1,900	16,718	0
Other Current Assets | Available-for-sale securities
Assets:
Total assets measured at fair value	187	177	187
Other Current Assets | Short-term investment
Assets:
Total assets measured at fair value	156	155	156
Other Current Assets | Hedge derivatives-Assets
Assets:
Total assets measured at fair value	140	22	161
Other Current Assets | Level 1 | Available-for-sale securities
Assets:
Total assets measured at fair value	187	177	187
Other Current Assets | Level 1 | Short-term investment
Assets:
Total assets measured at fair value	156	155	156
Other Current Assets | Level 1 | Hedge derivatives-Assets
Assets:
Total assets measured at fair value	0	0	0
Other Current Assets | Level 2 | Available-for-sale securities
Assets:
Total assets measured at fair value	0	0	0
Other Current Assets | Level 2 | Short-term investment
Assets:
Total assets measured at fair value	0	0	0
Other Current Assets | Level 2 | Hedge derivatives-Assets
Assets:
Total assets measured at fair value	140	22	161
Other Current Assets | Level 3 | Available-for-sale securities
Assets:
Total assets measured at fair value	0	0	0
Other Current Assets | Level 3 | Short-term investment
Assets:
Total assets measured at fair value	0	0	0
Other Current Assets | Level 3 | Hedge derivatives-Assets
Assets:
Total assets measured at fair value	0	0	0
Other Non-current Assets | SERP assets - employer
Assets:
Total assets measured at fair value	1,130	860	1,262
Other Non-current Assets | SERP assets - employee
Assets:
Total assets measured at fair value	42,298	38,170	38,970
Other Non-current Assets | Level 1 | SERP assets - employer
Assets:
Total assets measured at fair value	1,130	860	1,262
Other Non-current Assets | Level 1 | SERP assets - employee
Assets:
Total assets measured at fair value	42,298	38,170	38,970
Other Non-current Assets | Level 2 | SERP assets - employer
Assets:
Total assets measured at fair value	0	0	0
Other Non-current Assets | Level 2 | SERP assets - employee
Assets:
Total assets measured at fair value	0	0	0
Other Non-current Assets | Level 3 | SERP assets - employer
Assets:
Total assets measured at fair value	0	0	0
Other Non-current Assets | Level 3 | SERP assets - employee
Assets:
Total assets measured at fair value	0	0	0
Other non-current liabilities | SERP liabilities - employee
Liabilities:
Total liabilities measured at fair value	42,298	38,170	38,970
Other non-current liabilities | Contingent consideration
Liabilities:
Total liabilities measured at fair value	1,900	16,718
Other non-current liabilities | Defined Benefit Plan Assets
Assets:
Total assets measured at fair value	32,244	33,223
Other non-current liabilities | Level 1 | SERP liabilities - employee
Liabilities:
Total liabilities measured at fair value	42,298	38,170	38,970
Other non-current liabilities | Level 1 | Contingent consideration
Liabilities:
Total liabilities measured at fair value	0	0
Other non-current liabilities | Level 1 | Defined Benefit Plan Assets
Assets:
Total assets measured at fair value	0	0
Other non-current liabilities | Level 2 | SERP liabilities - employee
Liabilities:
Total liabilities measured at fair value	0	0	0
Other non-current liabilities | Level 2 | Contingent consideration
Liabilities:
Total liabilities measured at fair value	0	0
Other non-current liabilities | Level 2 | Defined Benefit Plan Assets
Assets:
Total assets measured at fair value	0	0
Other non-current liabilities | Level 3 | SERP liabilities - employee
Liabilities:
Total liabilities measured at fair value	0	0	0
Other non-current liabilities | Level 3 | Contingent consideration
Liabilities:
Total liabilities measured at fair value	1,900	16,718
Other non-current liabilities | Level 3 | Defined Benefit Plan Assets
Assets:
Total assets measured at fair value	32,244	33,223
Accrued Liabilities | Hedge derivatives-Liabilities
Liabilities:
Total liabilities measured at fair value	71	156	481
Accrued Liabilities | Level 1 | Hedge derivatives-Liabilities
Liabilities:
Total liabilities measured at fair value	0	0	0
Accrued Liabilities | Level 2 | Hedge derivatives-Liabilities
Liabilities:
Total liabilities measured at fair value	71	156	481
Accrued Liabilities | Level 3 | Hedge derivatives-Liabilities
Liabilities:
Total liabilities measured at fair value	$ 0	$ 0	$ 0